Arsenal booked their place in the knockout stages of the Champions League by claiming a 3-0 victory over Olympiacos in Greece.
The Gunners needed to win by a two-goal margin to progress, and Olivier Giroud gave them the lead in the first half when he headed in from Aaron Ramsey's cross.
Giroud grabbed his second of the match to put Arsenal in command four minutes after the break with a composed finish after being played through by Joel Campbell.
The Frenchman then completed his hat-trick from the penalty spot, after Omar Elabdellaoui handled inside the box, to ensure that the Gunners leapfrogged their opponents in Group F to reach the last 16.
Find out how the action unfolded below.
Hello everyone! It's the final matchday of this season's group stage in the Champions League and there is still everything to play for. Two teams who can make the knockout stages are Arsenal and Olympiacos, who will battle it out for a spot in the last 16 in Greece tonight.
It really is win or burst for Arsenal this evening, as they need to claim a victory by a two-goal margin or a high scoring one-goal triumph after their 3-2 defeat to the Greek side earlier this season. They have lost on their last three trips to the Karaiskakis Staium and a growing injury list has not helped their cause.
Meanwhile, Olympiacos will go through to the last 16 if they maintain their unbeaten home record against the Gunners. They have been invincible in their domestic league this season, but they will be looking to recover from a heavy defeat away to Bayern Munich last time out in Europe.
There has been plenty of focus on Arsenal's injury problems in recent weeks and it has left Arsene Wenger short of some key players. With that in mind, lets take a look at which line up the Gunners boss has been able to field this evening as the team news has arrived!
OLYMPIACOS XI: Roberto, Da Costa, Elabdellaoui, Siovas, Masuaku, Milivojevic, Fortounis, Kasami, Pardo, Seba, Ideye
ARSENAL XI: Cech, Bellerin, Mertesacker, Koscielny, Monreal, Ramsey, Flamini, Ozil, Campbell, Walcott, Giroud
OLYMPIACOS SUBS: Kapino, Botia, Salino, Dominguez, Cambiasso, Finnbogason, Hernani
ARSENAL SUBS: Ospina, Debuchy, Gabriel, Chambers, Gibbs, Oxlade-Chamberlain, Iwobi
So, that's how the two teams are looking this evening. As you can see, Arsenal are going for goals and they have brought Theo Walcott back into the starting lineup following his recent injury problems. Joel Campbell, who spent a season on loan at Olympiacos, will join him in supporting Olivier Giroud from out wide, with in-form Mesut Ozil also joining the attack.
With Francis Coquelin and Santi Cazorla both ruled out with long term injuries, Aaron Ramsey and Mathieu Flamini are the chosen pair in the centre of the pitch. There is also a familiar look to the back four, while Petr Cech starts in goal ahead of David Ospina, whose own-goal helped contribute to Arsenal's defeat in the reverse meeting.
Meanwhile, former West Brom striker Brown Ideye will lead the line for Olympiacos this evening. Pardo, who scored the opening goal at the Emirates, and Seba will support the Nigerian in the attack, with ex-Fulham man Pajtim Kasami also in from the start.
So, it's crunch time now for Arsenal who must win to ensure their progress to the knockout stages. They have not failed to make it out of the group for the past 15 years, but are very much on the cusp of dropping down to the Europa League when the competition resumes in the New Year.
They made a terrible start to their group campaign with a shock 2-1 defeat away to Croatian champions Dinamo Zagreb, and they followed that up by losing 3-2 to Olympiacos at the Emirates, which has left them needing to equal or better that result against the Greeks, or secure a win by a two-goal margin this evening in order to go through.
With no points on the board, they were written off as Bayern Munich visited the Emirates, but late goals from Olivier Giroud and Mesut Ozil helped to seal an impressive 2-0 win. However, their return meeting with the Germans didn't go as well, as they were thumped 5-1 at the Allianz Arena leaving them on the brink of an exit.
Arsenal were then left needing a win in their next match against Zagreb to stay in the tournament and they duly obliged by cruising to a 3-0 win. Despite the result, there was an element of frustration from supporters that they could not produce the same level of performance in their opening two games, where Arsene Wenger chose to rest a number of important first-team players.
Although they have struggled in Europe, the Gunners are currently firmly in the battle to claim Premier League glory this season. They are only two points away from top spot and warmed up for tonight's match by claiming a 3-1 win over Sunderland at the weekend.
Standing in the way of Arsenal and a place in the last 16 are Olympiacos, who are enjoying another dominant season in the Greek Super League. They have won every single one of their matches in the top flight and are already a huge 13 points clear of their nearest challengers.
It is perhaps no surprise that they are so far ahead, given that they have won the title for the past five seasons. They have also claimed the Greek championship in 17 of the last 19 campaigns, but despite their domestic success, they have failed to leave a mark on Europe.
They didn't get off to the best start in this season's tournament either after a 3-0 home defeat to Bayern, but they bounced back to record that impressive win at the Emirates. Two late victories over Zagreb have followed to leave them on nine points in the group and within touching distance of progressing.
Of course these teams played each other just a short while ago at the end of September. Felipe Pardo gave Olympiacos the lead with a deflected strike before Theo Walcott levelled things up. A horrific own-goal from David Ospinna saw the Greeks go ahead once more, but again Arsenal equalised as Alexis Sanchez headed in. However, less than a minute later Alfred Finnbogason scored a third goal of the evening for the visitors and they hung on to claim a vital three points.
That was Arsenal's first home defeat in seven games against Olympiacos, while they have lost all three of their trips to Greece. Each of those encounters at the Karaiskakis Stadium have come in the final group match, but unlike those previous occasions, the Gunners are not assured of their place in the latter stages this time.
We're just three minutes away from the start of the match and the two teams have made their way out onto the pitch. There is a deafening noise inside the ground, and it is all set up to be a memorable night of European football in Greece.
KICKOFF! We are underway at the Karaiskakis Stadium!
SHOT! Arsenal need to score goals this evening, but it's Olympiacos who have the first chance in the opening minutes. The Greek side put together a decent passing move on the edge of the box that leads to Seba being played into space, but the Brazilian can only blaze his strike harmlessly over the bar.
This is such a hostile atmosphere for the Gunners to play in, and it sounds like the whole ground are booing whenever they are on the ball. It could be a familiar noise this evening, as they are starting to rack up plenty of possession.
Although Arsenal are seeing more of the ball, they have not managed to work a chance on goal, and when their attacks break down the hosts look dangerous on the counter. On this latest occasion Sena charges forward with pace for Olympiacos, and is brought down by Bellerin as he looked to get into the box.
YELLOW CARD! From the resulting free kick it is played short to Pardo who sees his effort blocked. The ball eventually deflects through to Fortounis, who goes down under pressure from Flamini, but instead of a penalty the Greek midfielder picks up a booking for diving.
The threat of Olympiacos on the break shows again as Ideye is slipped in down the left and races beyond the defence. The striker then gets to the byline and tries to pull it back to one of his teammates in the middle, but Koscielny is in the right spot to cover and clear the danger.
Over the past few minutes it's the Greeks who have posed the most danger in the final third, with Arsenal looking rather open through the middle and down the flanks. The Gunners are yet to really pose any threat of their own, with Walcott, Giroud and Campbell seeing very little of the ball.
YELLOW CARD! Ramsey is shown the first card of the match for Arsenal for a lunging tackle from behind on Fortounis.
This is a lot better now from the Gunners, who are playing it around neatly inside their opponents' half of the pitch. They have started to put together some positive exchanges between their attacking players, with room opening up for them down the right-hand side of the pitch.
SHOT! Pardo has looked lively down the flanks this evening and he causes panic for the Gunners again when he bursts past Monreal. He then cuts inside and picks out Seba on the edge of the box, but the forward is only able to curl his attempt high over the bar.
One of the tactics from Arsenal tonight seems to be trying to pick out Giroud with long balls from the back. It is not a ploy that is working too well at the moment, as the Frenchman has struggled to win any of his challenges against the Olympiacos defence, and his frustrations are evident to see.
OFF THE BAR! Arsenal are within inches of grabbing a vital goal as Campbell is slipped in down the right, before bursting into the box. He then looks up and picks out the arriving Flamini, who places his first-time effort against the bar. Moments later the ball is swung back into the back for Giroud, but the Frenchman sees his header comfortably stopped by Roberto.
The Gunners have really started to crank up the pressure now and three men are up in the box as Ozil teases in a cross. However, Roberto comes off his line bravely to punch clear under pressure from Giroud as Olympiacos survive unscathed once again.
GOAL! Olympiacos 0-1 Arsenal (Olivier Giroud)
What a crucial goal this is for Arsenal, who now need one more strike to take them through to the last 16. Giroud is the man who finds the net, as he races to the front post to meet Ramsey's cross, before powering in a header that squeezes into the bottom corner, despite Roberto getting a hand on the ball.
SHOT! It's half a chance for Olympaicos, who win a corner and get plenty of men into the box. The set piece is eventually cleared to Pardo, who whips in a cross that Siovas can only head a few inches beyond the top corner.
It's not just the attacking side of the game that Arsenal have to get right, and at the moment they are back in numbers on the edge of their own box defending. The hosts do look a real threat whenever they come forward and have already shown their goalscoring prowess in this season's tournament.
Almost an opening for Arsenal, as Campbell's fine long ball picks out the run of Giroud. The Frenchman then heads it on towards Walcott, who looks to be through, but a slip at the last moment sees the attack break down.
SHOT! Walcott is involved again as he picks the ball up in the centre of the pitch and charges towards the box, with Giroud making a run to the left to take away two defenders and open up some space. The England international then gets to the edge of the box and drills in a low strike which he fails to catch cleanly and drags a few inches wide of the far post.
CHANCE! Olympiacos come mighty close to scoring an equaliser before the break as Pardo makes another good run down the right. He gets into the box and whips in a teasing cross that Koscielny stretches a leg out to meet and turn a few inches over his own bar.
Ramsey is going to have to be careful, as he goes in with another challenge that sees Masuaku go to ground. It was not a yellow card offence, but having already been booked it would be a major blow for him to be sent off and leave his team down to 10 men.
HALF-TIME: Olympiacos 0-1 Arsenal
It's so far, so good for Arsenal, who have a vital lead in this must-win Champions League tie. Olivier Giroud's header has given them a slender advantage over Olympiacos, and they now need one more goal to secure their place in the knockout stages at the Greek side's expense.
The Gunners have played some good stuff this evening and they are dominating the ball with 57% of the possession. They have only managed four shots on goal, to the eight attempts that Olympiacos have managed, but none of the home side's efforts have caused too many problems for Petr Cech.
In tonight's other Group F match, Bayern Munich are currently being held to a goalless draw by Dinamo Zagreb. Elswhere, Chelsea are 1-0 up against Porto and heading towards the last 16, while European Champions Barcelona are level at 1-1 with Bayer Leverkusen.
RESTART! Olympiacos take the kick off for the second half and get the match back underway!
Arsenal are forced to defend in the opening moments of the half, as a brilliant cross from Pardo is headed behind by Mertesacker. From the resulting corner, Cech comes out to punch the ball away, as they eventually manage to clear the danger.
Real concerns here for Arsenal, as Giroud goes down and looks in real pain as he holds onto his ankle. He receives some treatment from the medical staff, but is now back on the pitch, although we will have to wait and see whether he can stay on for the rest of the evening.
GOAL! Olympiacos 0-2 Arsenal (Olivier Giroud)
Giroud shows no signs of his injury worry as he scores his second goal of the evening to put Arsenal on the verge of a knockout place! The Frenchman races into the box and onto a wonderful threaded pass from Campbell, before keeping his composure to slide a fine low effort into the bottom corner.
CHANCE! Huge chance for the Greeks to level the scores as Da Costa rises above everyone to meet a corner that was flicked into his path. He makes good contact with the ball, but he can only direct it straight at Cech, who makes the save and holds on under pressure.
It will be interesting to see how Arsenal play for the rest of the match, as this scoreline will be enough to take them through to the last 16. They look full of confidence at the moment, while in contrast their opponents' seem to be really struggling to gain any sort of momentum as they now search for an important goal.
CHANCE! It's very nearly three for Arsenal as a deep cross causes huge problems for the Olympiacos defence. The ball eventually drops to Walcott at the back post, but his drilled effort towards the far corner takes a slight deflection and heads inches wide of the target.
SAVE! What a great save this is by Cech to preserve Arsenal's two-goal lead. Fortounis does well to find space just outside the box, before bending in a fine strike that looks headed for the top corner until Cech stretches out a big arm to turn the ball over the bar.
Arsenal are finding so much space deep in the Olympiacos half and this time Walcott picks the ball up just outside the box. Instead of taking on a shot, he looks to slide Giroud through on goal, but his final pass lets him down and the hosts are able to clear.
YELLOW CARD! Giroud is the latest Arsenal player to be cautioned after a foul on Pardo. A look at the replay shows it was a harsh call from the referee, as there was very little contact between the two players.
SHOT! Olympiacos are enjoying their best spell of the match and they are swinging a number of dangerous balls into the box. One of those deliveries is cleared to Kasami on the edge of the area, but the Swiss international sees his low drive easily saved by Cech.
PENALTY TO ARSENAL! The Gunners are awarded a penalty as Monreal's low strike is blocked by the hand of Elabdellaoui inside the box. The defender is also booked for the infringement, while Giroud steps up to try and score a third from the spot.
GOAL! Olympiacos 0-3 Arsenal (Olivier Giroud)
Giroud makes no mistake with the penalty and confidently slots the ball into the bottom corner for his, and Arsenal's, third goal of the evening. This has been a wonderful performance from the Gunners and their French striker has silenced many of his doubters too this evening.
That third goal has silenced the passionate home crowd at this ground, and the voices of the Arsenal supporters are all that can be heard. It has been a hugely impressive display by the Gunners, who are surely going to continue their record of making it out of the group.
SUB! It's a first change of the match for the Greeks, as Dominguez comes on to replace Kasami.
SUB! There is also a substitution being made by Arsenal, as Walcott heads off to be replaced by Gibbs.
Campbell has been brilliant for Arsenal this evening and the Costa Rican takes the ball from the halfway line and charges through the midfield. He then slides in Giroud, who sees a low shot blocked by the keeper, but the Frenchman was standing in an offside position anyway.
SUB! Olympiacos make their second change of the evening, as Hernani is now on to replace Sena.
Olympiacos look a beaten team at the moment, and there is every chance of Arsenal adding more goals against their faltering backline. The Gunners look so calm and confident on the ball at the moment and the players who have been brought in due to injuries have also done incredibly well.
This will surely go down as one of the greatest away displays from Arsenal in the Champions League. They have won against the likes of Real Madrid, AC Milan and Bayern Munich in recent seasons, and although Olympiacos are not up to the same standard, it is still as impressive from Wenger and his players.
SUB! Finnbogason is coming on for the closing stages for Olympiacos in place of Pardo.
CHANCE! Olympiacos almost pull a goal back late on as a cross from Ideye is headed towards his own goal by Koscielny. The ball looks to be dropping under the bar, until Cech gets back and helps it over the top.
There will be at least four minutes of stoppage time.
SUB! Oxlade-Chamberlain comes on to help Arsenal over the line in place of Campbell, who has enjoyed his best game in an Arsenal shirt.
SUB! Another of Arsenal's standout players from the evening comes off, as Giroud is replaced by Chambers.
FULL-TIME: Olympiacos 0-3 Arsenal
The final whistle blows in Greece, where Arsenal have claimed a 3-0 win over Olympiacos to book their place in the last 16 of the Champions League. A hat-trick from Olivier Giroud has sealed their progress on what will go down as a famous European night for the Gunners.
I'm afraid that's all we've got time for this evening. I'll be back in a short while to bring you analysis and player ratings from tonight's match, while we will also have the news and reaction to this evening's other Champions League games. I hope you have enjoyed our coverage. Goodbye!
