Good evening! Thank you for joining Sports Mole for tonight's Champions League encounter, and what a treat it promises to be as the round-of-16 concludes with a match which has provided some classic contests in recent years.

Barcelona hold the slight advantage heading into tonight's game courtesy of the 1-1 draw in the first leg at Stamford Bridge last month, but they know from experience that Chelsea are capable of getting a result here.

It promises to be another memorable night of European football, so let's waste no time in getting started with a look at the team news...

BARCELONA STARTING XI: Ter Stegen; Roberto, Umtiti, Pique, Alba; Rakitic, Busquets, Iniesta; Dembele, Suarez, Messi

BARCELONA SUBS: Cillessen, Paulinho, Alcacer, Digne, Gomes, Vidal, Vermaelen

CHELSEA STARTING XI: Courtois; Azpilicueta, Christensen, Rudiger; Moses, Kante, Fabregas, Alonso; Hazard, Giroud, Willian

CHELSEA SUBS: Caballero, Morata, Pedro, Bakayoko, Zappacosta, Cahill, Emerson

What can we make of those two teams, then?

Well, we'll start with the home side and the headline news is that Andres Iniesta - hailed as a "genius" by Chelsea boss Antonio Conte prior to this game, does indeed start in midfield having passed a late fitness test just hours before the match.

Iniesta picked up a hamstring injury against Atletico Madrid earlier this month and had been a major doubt for today's game, but the veteran has managed to recover in time and takes his place in a midfield three alongside Rakitic and Busquets.

Another key man returning the starting lineup for tonight's hosts is a certain Lionel Messi, who missed the weekend win over Malaga due to the birth of his third child.

Much was made of the Argentine's goalless record against Chelsea before the first leg, but his away goal at Stamford Bridge - which was his first strike in nine meetings with the Blues - could prove crucial in this tie.

He has now scored in his last four appearances for the club, after a drought prior to that Chelsea game, and he also has more goals against English opposition than any other player in Champions League history, notching 18 times against Premier League clubs.

Should Chelsea somehow manage to nullify the maestro Messi then there are plenty of other dangermen who could step up to the plate, with Ousmane Dembele among those to come into the side tonight after missing the first leg.

Luis Suarez will also be a threat, of course, and he has plenty of history against Chelsea already, infamously sinking his teeth into Branislav Ivanovic during one game while at Liverpool. Suarez scoring twice in his six games against Chelsea during his stay at Anfield, but so far in 2018 he has netted 14 times in 17 appearances across all competitions.

However, the Uruguayan has been uncharacteristically quiet in this competition, failing to score in his last 881 minutes - his longest ever Champions League drought. Indeed, he has scored in this competition since the memorable win over PSG a year ago.

Dembele in for Paulinho is the only personnel change made by Ernesto Valverde from the first leg, but there will also be a change in system as Barca go 4-3-3 again, having opted for a 4-4-2 formation at Stamford Bridge.

Paulinho drops to a bench which, of course, does not include Philippe Coutinho, who is ineligible for Champions League action having already played in this season's competition for Liverpool.

As for Chelsea, the headline from Antonio Conte's team selection once again revolves around their striking situation, and this time Olivier Giroud has been chosen to lead the line for the Blues at the Camp Nou.

It is a bold choice from Conte considering Giroud is yet to score a Premier League goal for the club and has not started many games at all this season - including his time at Arsenal - but he has clearly lost faith in Alvaro Morata and the Spaniard is once again left on the bench this evening. One has to question his future at the club beyond the summer if that continues.

One man who will be happy with the inclusion of Giroud is Eden Hazard, who has been very vocal about his dislike for the false nine role he has been forced to play on occasion when Conte has left both Morata and Giroud out.

That system worked well enough in the first leg of this tie, but Hazard really struggled against Man City recently and it certainly isn't his best position. The Belgian has set his teammates up for a shot on 23 occasions in the Champions League this season - the joint-most alongside Neymar - but he is without a goal himself in his last four, having scored six in six prior to the first leg.

It was Willian, rather than Hazard. who proved to be the main threat to Barcelona's defence at Stamford Bridge, with the Brazilian not only scoring Chelsea's goal in that match, but also hitting the post twice prior to breaking the deadlock.

Willian has continued that good form since the first leg too and comes into this match with five goals in his last five outings across all competitions. Six of his nine Champions League goals for Chelsea have come from outside the box, meanwhile, which is more than any other player has managed from range in the competition since he joined the Blues in 2013.

Former Barcelona man Pedro is the only player to drop out of the side which started the first leg as Giroud comes in for the Spaniard, but there is another Barca alumnus in the Chelsea side, with Fabregas having made 96 league appearances for the club after rejoining them from Arsenal.

N'Golo Kante will again be charged with keeping Barca's dangerous attackers quiet, while Andreas Christensen once again gets the nod in defence despite some mistakes of late. Antonio Rudiger, meanwhile, has recovered from muscle fatigue to replace Cahill in the side.

There is plenty of quality on both sides, then, but Barcelona will come into this match as the favourites by virtue of their away goal and their home advantage - although if they learned anything from the first leg then it will be that Chelsea are not to be taken lightly.

The Catalan giants were second best for much of that match at Stamford Bridge and were somewhat fortunate to come away with a draw which keeps them well on track for a treble this season, having also reached the Copa del Rey final.

Domestically, things could not be going much better for Barca in Ernesto Valverde's debut season at the helm. Barca have set a La Liga record by going 28 games unbeaten from the start of the season, and they remain the only team in Europe's top five leagues yet to lose a league game in 2017-18.

That form has helped them to build an eight-point lead over second-placed Atletico Madrid, but even more satisfying for Barcelona will be the 15-point lead they enjoy over bitter rivals Real Madrid. If they can also beat Los Blancos to the Champions League title then it will more than make up for last season.

Barcelona's form extends further than just La Liga, though, and they come into this match unbeaten in their last 14 games across all competitions, stretching back to a 1-0 defeat at city rivals Espanyol in January - although that Copa del Rey loss did not prevent them from progressing through to the next round.

Indeed, that defeat is Barca's only reverse in 44 outings since their season got off to the worst possible start with back-to-back defeats at the hands of Real Madrid in the Super Cup. After those results, and losing Neymar to PSG, not many would have expected Barcelona to be in such a strong position at this stage of the campaign.

Barcelona are not playing the type of football which saw many hail them as the greatest team of all time under Pep Guardiola, but Valverde's side are getting results and crucially they look stronger defensively than they have for some time.

Only the always-miserly Atletico Madrid have conceded fewer goals in La Liga this season, while no team can beat Barca's record of just two goals conceded in the Champions League this term - one of which came in the reverse fixture.

Indeed, Barca have kept six clean sheets during an eight-match unbeaten run in this competition, although they have drawn three of their last four outings in the Champions League this season.

A goalless draw or a win tonight would be enough to send them through to the quarter-finals for a record-extending 11th year in a row, although their last two defeats at this stage have come at the hands of English opposition - including a 2005 loss to Chelsea. At this stage last season Barca produced the biggest comeback in Champions League history to beat PSG 6-1 in their second leg here, only to then lose to Juventus in the next round.

For all of their star quality, it is Barcelona's home record which is arguably the most daunting thing Chelsea will have to overcome tonight, with the Catalan outfit having gone 20 games without defeat in front of their own fans in the build-up to this one.

Indeed, the August loss to Real Madrid in the Super Cup is Barcelona's only home defeat in their last 47 matches here - a run which stretches back to September 2016 - while their Champions League record is even more formidable with 18 wins and one draw from their last 19 Camp Nou outings in this competition.

Atletico Madrid and Juventus are the only visiting teams to avoided defeat here in Barcelona's last 24 Champions League home games - both gaining draws - while Bayern Munich's 3-0 win at the Camp Nou in May 2013 is Barca's only home Champions League loss of the decade.

Looking even further back, the Blaugrana have only ever lost four of their 39 Champions League knockout games at home, while Liverpool in February 2007 the only English team to inflict defeat on such a stage.

That is the size of the task which awaits Chelsea tonight, then, and the stats don't look particularly good for them either, with 68% of away sides who have draw the first leg of a Champions League knockout tie 1-1 going on to progress to the next round.

That said, Chelsea have won four of the six European ties in which they have drawn the first leg, including three of the four where the scoreline of that first leg has been 1-1. The most recent of those also came against Spanish opposition, beating Valencia in the 2006-07 round of 16.

There is precedent for Chelsea tonight, then, and particularly at this stadium where they themselves enjoyed one of the most memorable nights in the club's history, but it will not be Frank Lampard, John Terry, Didier Drogba and co visiting the Camp Nou tonight, and the current crop of players are going through a very mixed run of form at the moment.

So far in 2018 Chelsea have only won five matches inside normal time, with six draws and five defeats in that time too. That includes back-to-back league defeats after their 1-1 draw in the first leg, although they did return to winning ways against Crystal Palace on Saturday.

Chelsea do not only have a battle on their hands to stay in the competition this season, they have a lot of work to do if they are to grace it with their presence next term too, with four points currently separating them from fourth-placed Liverpool in the Premier League table.

The Blues are 16 points worse off than at the same stage of last season - leading to plenty of speculation over Antonio Conte's future - although a victory at the Camp Nou this evening would make things look a lot better in West London.

Chelsea only managed a second-placed finish in Group C, ending up level on points with Roma but missing out on top spot due to their head to head record. They did finish four points clear of Atletico Madrid, though, and notably won at the Wanda Metropolitano, which may stand them in good stead this evening.

Only PSG and Liverpool scored more goals throughout the group stages, although it should be noted that 10 of their 16 strikes came against Qarabag, and they also conceded eight goals in their six group games.

Chelsea have also only won one of their last five Champions League games, and their last nine outings in this competition have produced a very mixed bag of three wins, three draws and three defeats - not the type of record which will take them all the way to Kiev for the final.

It is a similar story away from home in Europe, where Chelsea have had an even split of wins, draws and defeats from their last 15 Champions League outings on the road. Victory tonight would see them win back-to-back away games in this competition for the first time since August 2013.

Even that is a significant improvement on their general home form, though, and Chelsea will arrive at the Camp Nou - arguably the hardest place to visit in Europe - having lost their last four away games across all competitions and with only one win in their last eight.

It is a major dip in form from seven wins in their first nine away games this term, and another defeat this evening would see them fall to five in a row for the first time since a run of six came to an end in December 2000.

Chelsea were, of course, absent from European football last season for the first time since 1996-97 - and from the Champions League for the first time since 2003-04 - and their recent record in the knockout stages of the competition - since winning it in 2012 - has been fairly poor.

The Blues have only progressed into the quarters once in the last five seasons and were beaten by PSG at this stage in 2014-15 and 2015-16. However, their overall last-16 record stands at eight wins and four defeats from their previous 12 such ties.

PREDICTION: Right, we're 10 minutes away from kickoff at the Camp Nou now, which means that it is time for a prediction!

Chelsea have shown that they can get a result here in the past, and they have the tools to be capable of doing it again tonight, but it is impossible to ignore their recent away record, especially considering Barca are so strong at home too. This fixture has thrown up some classic moments and fixtures in recent years, and hopefully we will see more tonight, but at the end of it all I'm backing Barca to come out on top.

SPORTS MOLE SAYS: Barcelona 2-0 Chelsea

Chelsea do seem to be Barcelona's main bogey team, though, and they are unbeaten in their last eight meetings with them in the Champions League - winning two of those and drawing six, including four consecutive stalemates here at the Camp Nou.

The fixture instantly conjures up images in the mind of Ronaldinho's genius goal, Iniesta's last-minute winner at Stamford Bridge and Fernando Torres's breakaway strike in 2012, the latter of which was the last time these two sides met before the first leg.

Despite Chelsea's very respectable record against Barcelona, the Spanish giants do still have the upper hand in with three wins from their five previous two-legged ties against the Blues in the Champions League - although in the last 16 it currently stands at one win apiece.

Only two fixtures - Bayern Munich vs. Real Madrid and Barcelona vs. AC Milan - have been played more often in the Champions League than this one, so it really is one of the competition's great rivalries.

Barcelona have only ever lost two of their 32 previous home games against English opposition, though, and are unbeaten in their last seven - although the only one they failed to win in that time was the 2-2 draw against Chelsea in 2012. Barca have also won 23 games against Premier League teams in the Champions League, which is more than any other club has managed in the competition.

Chelsea, meanwhile, have won four, drawn seven and lost five of their trips to Spain, although they are unbeaten in their last 10 visits stretching back to November 2005.

Right, the players are out, the anthem is blaring and it's just about time to get started here! A reminder of the team news before we do get underway...

BARCELONA STARTING XI: Ter Stegen; Roberto, Umtiti, Pique, Alba; Rakitic, Busquets, Iniesta; Dembele, Suarez, Messi

CHELSEA STARTING XI: Courtois; Azpilicueta, Christensen, Rudiger; Moses, Kante, Fabregas, Alonso; Hazard, Giroud, Willian

KICKOFF: Here we go, then! Who will become the final name in the hat for the quarter-finals? Barcelona get us underway at the Camp Nou!

Oh it is a nightmare start for Chelsea as Lionel Messi makes it two goals against Chelsea - and it has taken only three minutes of the second leg!

Messi often makes goalkeepers look stupid, but Courtois really should do a lot better here. Barca get a stroke of luck on the way through as Messi's first attempt at a one-two is blocked, but falls kindly for Suarez, who then plays Messi in down the right channel. It looks like an impossible angle, but Messi sneaks it through the legs of Courtois, who simply has to save it from there.

That goal is a huge blow for Chelsea, of course, but it doesn't really change their task tonight. They knew they needed to score here, and that is still the case.

Chelsea look for a quick response as Willian whips a free kick in towards the near post which takes a deflection off a Barcelona man on the way through before going into the side-netting.

It is a new record for Messi! And an extension of his incredible record against English opposition too...

This has been a really good response from Chelsea to falling behind, and they almost get in down the right flank here until Iniesta stops the move with an inch-perfect sliding challenge inside his own area.

Chelsea will certainly be encouraged with their response to that early goal. Since Messi snuck the ball between the legs of Courtois Chelsea have looked much the more likely to add the game's second goal.

SAVE! Ter Stegen is called into action for the first time tonight as Willian drills a low strike towards the bottom corner, but the Barcelona keeper gets down well to make the save and crucially holds on to it too.

Here is that Messi opener - a stroke of luck, a goalkeeping error and a 99th Champions League goal for the maestro.

Chelsea certainly haven't let their heads drop after falling behind so early. They look very up for this one, hounding Barcelona to win the ball back and then looking to get forward quickly.

Barcelona have slowly begun to sap the fightback out of Chelsea here, taking control of possession and just knocking it about themselves. They are happy to slow the tempo of the game right down.

What a way to get your first ever Barcelona goal! Dembele opens his account with Barca's second goal of the night, and it comes at the end of a devastating counter-attack, with Messi again the inspiration.

The Argentine steals possession from Fabregas on the halfway line before getting his tow to the ball just in front of Christensen and Azpilicueta to send him down the left. He then takes his time and knocks a square ball across the box for Dembele, who takes his time before hammering a brilliant finish into the top corner.

That goal means that we can no longer have extra time tonight, and means that Chelsea need two goals without conceding any more. Hazard had threatened second before that goal, but his effort was well blocked by Umtiti.

YELLOW CARD! Sergi Roberto becomes the first player in the book this evening for a cynical foul on Hazard.

Here is that second goal for Dembele for your viewing pleasure.

The assist. The composure. The finish. Brilliant.

Chelsea's heads didn't drop after that first goal, but they may start to now as Barcelona begin to play some party football. They are knocking the ball around beautifully at the moment.

CHANCE! What a goal this would have been. After a lengthy spell of possession Barca finally find a way through the Chelsea defence again as Iniesta back-heels it to Suarez. Courtois is quickly off his line, though, and is able to deny the striker from close range.

Chelsea are on the ropes a little here. Barcelona are pushing for a third goal and they look more than capable of getting it.

Azpilicueta has the chance to put the ball in the box for Giroud, who has barely had a kick so far tonight, but the defender's cross is poor and Ter Stegen claims it.

CHANCE! Messi wins a free kick on the touchline and takes it himself, swinging a dangerous cross into the near post which Pique is just short of getting on the end of. Pique had got the wrong side of Chelsea's defence there!

Barcelona are in complete control of this match now. Chelsea seemed ready, willing and able to fight back after the opening goal, but that second for Barca seems to have killed their hope off.

Iniesta does well to work space for himself to shoot, but he drags his effort well wide of the target.

CHANCE! This is more like it from Chelsea! One goal back would certainly make things interesting, and they almost get it here as Willian darts down the left flank before pulling the ball back for Alonso. The Spaniard fires his effort straight at Ter Stegen, though, and Umtiti blocks the follow-up effort from Giroud.

CHANCE! Another big chance for Chelsea! This time Kante skips through a couple of challenges on his way into the box, but he then takes the ball off the toe of Fabregas, who is in a better position, and drags his shot wide.

There have been a couple of signs that this tie is perhaps not quite dead yet in the last few minutes. At 2-1 suddenly the whole balance of the tie swings as a second goal would then send Chelsea through. The next goal is going to be pivotal tonight.

Really good work from Willian again as he darts in between two defenders, but the attempted one-two with Giroud breaks down with a poor return pass from the Frenchman. Willian has looked bright again for Chelsea tonight.

Giroud throws himself to the floor following a touch from Umtiti, gifting Chelsea a free kick in a very good position...

YELLOW CARD! Before it can be taken, Willian goes into the book for complaining that the wall is not the full 10 yards away.

OFF THE POST! Chelsea are inches away from getting themselves back into this match on the stroke of half time! Alonso curls the free kick towards the top corner and Ter Stegen is getting nowhere near it, but the ball clips the outside of the post.

The first half comes to an end at the Camp Nou, and it is Barcelona who go into the break with the lead on the night and control of the tie.

The scoreline doesn't really tell the full story of the game as Chelsea have looked capable of scoring, but the hosts have been ruthless and have punished Chelsea's mistakes to leave themselves in command of this one.

The opening goal took just 128 seconds to arrive as Messi's original one-two fell kindly for Suarez, who played it back to Messi down the right channel.

There didn't appear to be much danger at that stage with the angle against Messi to no-one really to aim for in the middle, but he just got his shot on target and it snuck between the legs of Courtois, who should have done a lot better at his near post.

Messi was instrumental for Barcelona's second goal too, stealing possession from Fabregas on the halfway line before tearing past Christensen and Azpilicueta on his way towards the box.

It looked as though the Argentine was going to do it all himself, but he then slowed things down and waited for support, eventually laying the ball into the path of Dembele, who picked out the top corner with a fine finish for his first Barcelona goal.

The way that first half has gone, Barcelona will be feeling that they need a third to make things absolutely certain tonight, and the next goal is going to be crucial here.

Chelsea have looked capable of scoring, with Willian, Marcos Alonso and N'Golo Kante all threatening for the visitors. The closest they have come came right at the end of the half when Alonso curled a free kick over the wall which would have left Ter Stegen no chance, only to see it clip the outside of the post.

KICKOFF: Chelsea get us back underway for the second half!

CHANCE! Mistakes cost Chelsea in the first half, and they almost shoot themselves in the foot again here. Courtois's poor pass gifts the ball straight to Suarez, but the keeper then redeems himself by denying the striker.

CHANCE! Brilliant defensive work from Dembele, of all people! Chelsea break forward and find themselves with an overlap, but they always look a little hesitant and Giroud's final ball to Alonso is weak enough to allow Dembele to make a last-ditch sliding tackle. Not clinical enough again from the visitors.

PENALTY SHOUT! Big shout for a penalty for Chelsea as some brilliant interplay between Willian and Hazard ends with the former playing a ball in to Alonso. The full-back finds himself the wrong side of Pique and goes down under his challenge, but the referee says no! It looked like a decent shout at first, but the replay shows that there wasn't really enough contact to warrant a spot kick. Giroud is booked for his complaints.

This has been a really good start to the half from Chelsea, who have played pretty well tonight with the exception of the mistakes for which they have been punished.

Kante floats a cross into the box which Alonso meets with a spectacular bicycle kick, but it comes off his shin. Alonso is popping up everywhere at the moment!

We're 10 minutes into the second half now, and Chelsea have been by far the better team since the interval. They have come out of the blocks really well, but they need to find that killer touch in the final third.

BARCELONA SUB: Barcelona make the first change of the night and Iniesta gets a rousing reception as he is replaced by Paulinho.

Barca have not been themselves in this second half so far. They have barely had any lengthy spells of possession since the interval and have been on the back foot - a dangerous game to play with so long left in the match.

Moses wastes a good attacking position for Chelsea down the right flank with a poor low ball into the box which is blocked by Alba. Barcelona immediately break, but Messi's through-ball is just too heavy for Dembele.

BARCELONA SUB: Barcelona are forced into another notable change here as Busquets limps off to be replaced by Andre Gomes.

Alonso again pops up in the Barcelona area as they work the ball across to him, but Pique throws himself in front of the resulting effort.

Just like that, it is game over. Chelsea have been by far the better team in this second half, but suddenly their chances are surely over.

Suarez comes forward down the middle but then waits for Messi to join him. He pokes the ball into his path and Messi just makes it look so easy to coast past two Chelsea defenders before again firing the ball through the legs of Courtois. It is his 100th Champions League goal!

BARCELONA SUB: Barca make their third and final change of the match as Aleix Vidal replaces Dembele.

CHELSEA SUBS: Chelsea also make a double change, with Davide Zappacosta and Alvaro Morata replacing Moses and Giroud.

Chelsea have actually probably been the better team for the majority of this game, but Barca have just been so clinical and that is what separates the two sides. That and the genius that is Messi, of course.

A reminder that Chelsea need three goals in the final 20 minutes of this game. They have looked dangerous tonight, and certainly capable of scoring one or two, but this is too much for them to do now.

Barcelona are now just knocking the ball about amongst themselves, waiting for Chelsea to chase it and come out of their position. The hosts are in complete control.

YELLOW CARD! Marcos Alonso goes into the book for a high boot on Paulinho while trying to block a clearance.

Hazard makes a good break down the right as he latches on to Fabregas's pass before playing a low ball into the middle, but there are no white shirts within 20 yards of him.

SAVE! Barcelona win a free kick which may not be in shooting range for most people, but of course Messi tries his luck. His effort takes a deflection off Willian on the way through, and Courtois palms it behind for a corner.

Hazard again darts into a good position, but his final pass goes behind Willian and Barcelona are able to clear. The end product just hasn't been there for the visitors tonight.

CHELSEA SUB: Pedro will get a runout on his return to the Camp Nou, replacing Hazard to a brilliant ovation.

Messi is now staying up front in search of his hat-trick goal, and you can't blame him. He has been the difference again tonight.

CHANCE! Poor marking from Chelsea as Paulinho is left completely unmarked from a corner, but Courtois pulls off a good reaction save to deny the midfielder's header.

Just three minutes of this match remaining now, but in truth it has been all over since that third goal - and both sides know it.

SAVE! Zappacosta looks to provide a late consolation for Chelsea, but Ter Stegen gets down well to make the save.

OFF THE BAR! Things may well have been different today had Chelsea also got the rub of the green. They hit the woodwork for the second time as Rudiger climbs highest in the area and plants his header against the crossbar.

There will be two minutes of added time at the end of this match.

The referee puts Chelsea out of their misery as their 2017-18 Champions League campaign comes to an end at the Camp Nou, where they have fallen victim to the genius of Lionel Messi.?

The Argentine created one and scored two himself - including his 100th Champions League goal - to fire Barcelona through to the quarter-finals courtesy of a 3-0 win on the night and a 4-1 win on aggregate. Dembele also scored his first Barcelona goal, but tonight it was all about Messi.

Right, that is all we have time for this evening!

Thank you very much for joining Sports Mole for tonight's Champions League clash between Barcelona and Chelsea as Lionel Messi shines in a 3-0 win for the hosts at the Camp Nou, sealing their place in the quarter-finals. I will leave you with our match report, and be sure to stick around for reaction too.

From me, though, it is goodbye for now!