Benfica hosted Olympiacos in Lisbon on Wednesday evening with both sides looking for a victory which would improve their respective bids to qualify for the knockout stages.
It was the visitors who were on top in the first half and they took the lead thanks to Alejandro Dominguez's calm finish.
However, Benfica managed to secure a point late on when Oscar Cardozo fired in an equaliser from close range in the 83rd minute.
Read below to find out how the drama unfolded in the Group C contest.
Good evening everyone. The Champions League continues tonight and I'll be bringing you coverage of the Group C clash between Benfica and Olympiacos.
It's a massive game for both sides tonight. Each team currently have three points and a win would be a big boost at the halfway point of the group stage. PSG look favourites for that top spot but both of these sides will fancy their chances of progressing.
BREAKING NEWS: We're still awaiting full team news but reports in the last few minutes suggest that Javier Saviola will not start against his former side.
BENFICA: Artur, A. Almeida, Luisao, Garay, Siqueira, Gaitan, Matic, Enzo Perez, Ola John, Lima, Cardozo
OLYMPIACOS: Roberto, Saline, Manolas, Siovas, Holebas, Maniatis, Samaris, Weiss, Dominguez, Fuster, Mitroglou
The big news is confirmed as Olympiakos field a starting lineup without Saviola but they will still carry an attacking threat tonight, with Konstantinos Mitroglou leading the line.
It looks like Saviola has been sacrificed for an extra creative midfielder. I must say I'm surprised by the decision but it could prove to be a great move from Michel.
Jorge Jesus has named a Benfica side which we pretty much expected to see tonight. Oscar Cardozo provides the goals but the midfield is where the hosts really impress.
In the other Group C game this evening, PSG travel to Anderlecht as they look to continue their 100% record in this season's competition.
BENFICA SUBSTITUTES: Lopes, Pereira, Vieira, Djuricic, Amorim, Rodrigo
OLYMPIACOS SUBSTITUTES: Megyeri, Ndinga, Medjani, Yatabare, Olaitan, Saviola, Campbell
The visitors have clearly got options on the bench, with Saviola and Joel Campbell both great replacements in their own way. Filip Djuricic, a substitute for Benfica, has a big future ahead of him and he's already impressed for Serbia.
These two teams face each other twice in the next two weeks and, in truth, they're probably the two games which will decide who follows PSG into the next round.
Can Benfica stop Mitroglou? The striker has already scored 13 times this season and his form tonight will be crucial. Recent reports have suggested that a few of Europe's top clubs are watching too.
Ola John and Lima will provide support for Cardozo. Vladimir Weiss and Chori will do the same for Mitroglou. We could be in for a very exciting evening.
There's plenty of action happening around Europe tonight. If you want to follow any other match, just click on the game in the box to the right.
It's a very, very wet evening in Lisbon. The players have been soaked during the warm up and the pitch will play a big part this evening.
Both teams have headed back inside to make their final preparations before the match begins. Just under 10 minutes until the action starts.
It's not the busiest you'll ever see the Estadio da Luz but the fans that have been brave enough to take on the rain will certainly be making a lot of noise.
The famous Champions League anthem has been played and both teams are ready for the game now. It's a very important night in Group C, who will come out on top in Lisbon?
Olympiacos will get the game underway.
Olympiacos immediately go for a long pass but Roberto's kick is wayward and Benfica win the ball back.
Olympiacos fail to clear their lines and Weiss gives away a free kick in a dangerous position.
SAVE! Cardozo drives the free kick towards the bottom corner but Roberto does superbly to push the ball past the post. The visitors are then fortunate to survive three corners in quick succession. Great start from Benfica.
CHANCE! Weiss cannot believe his luck when he's punished for what looks like a good tackle on Siquiera. The free kick falls to John, who whips in a dangerous cross but Luisao heads the ball over the crossbar.
CHANCE! Mitroglou beats the off side trap but he waits too long to pull the trigger and Luisao does just enough to prevent the visitors from taking the lead. Exciting start in Lisbon
Benfica are certainly playing the better football in the early stages of the game. The visitors are forced to deal with a couple of dangerous crosses but they need to start making an impact in midfield.
CHANCE! Olympiacos should be ahead. Fuster does superbly to beat a couple of defenders and he delivers an inviting ball into the area. Mitroglou gets to the ball first but the in-form forward fails to hit the target with his header. Benfica breathe a sigh of relief.
Both sides are wrestling for superiority in this game's opening minutes but neither have been able to take any of their early opportunities.
There's definitely been a few signs that the visitors are beginning to settle. Mitroglou is playing on the shoulder of the last defender but the Greeks must get a player closer to their lone striker.
Weiss displays some good skill to trick his way past a couple of defenders but he's caught in two minds just moments later and his delivery goes straight to Artur.
Great work from John, who exchanges passes with Almeida to break into the box. Roberto does well to collect a dangerous cross from the Dutchman.
The rain is falling heavily once again in Lisbon. These conditions could make it very difficult for the goalkeepers tonight. Perez escapes a booking for a wild challenge in the middle of the pitch.
Cardozo drifts out to the left in an attempt to launch a counter attack but a strange piece of improvisation from Gaitan sees the promising move end. John collects the ball on the right again and he's causing the visitors plenty of problems at the moment. No breakthrough yet.
Olympiacos are happy to play the game at a slower pace but Benfica are doing a good job of forcing the issue in midfield with good pressing.
Lima thinks he has a chance of opening the scoring when Perez plays a clever through ball but the assistant referee raises his flag to frustrate the home supporters. Good decision.
Mitroglou, having not seen much of the ball in the last few minutes, drops deeper to begin an Olympiacos attack. Plenty of patience being shown by the visitors though and Benfica are defending impressively.
SAVE! Mitroglou holds off a couple of challenges to earn himself some space but his low effort from outside the box is beaten away by Artur.
Cardozo attempts the spectacular finish inside the box as Benfica break in numbers but the referee decides that the striker's high feet were a danger.
Lima's low effort is easily blocked by Roberto but it doesn't matter as the assistant referee once again raises his flag on the far side.
Dominguez does very well to win a free kick in Benfica's half of the pitch when he fails to pick out any teammates. The visitors once again attack with patience but there's no way through on this occasion.
GOAL! BENFICA 0-1 OLYMPIACOS (DOMINGUEZ)
Olympiacos make the breakthrough! Mitroglou flicks the ball to Dominguez, who avoids one challenge with a great piece of skill before slotting the ball home. Great goal from the visitors.
That could prove to be a very important goal. Benfica must respond but their early efforts are dealt with well by the Olympiacos defence.
Weiss works hard on the left side of midfield to retrieve possession. Mitroglou is causing all sorts of problems with his strength and intelligence. The visitors almost create another opportunity but the final ball from Fuster skips out of play.
That opening goal has given Olympiacos some confidence. They're pressing high up the pitch now, which is causing problems for Matic and Perez in midfield.
Jorge Jesus does not look a happy man on the sidelines. He's screaming instructions at his team as the rain begins to fall even more heavily.
The conditions are getting worse with every minute that passes. Olympiacos are ending the first half strongly and have won a free kick on the right wing.
Holebas delivers an inviting cross into the box but Benfica do well to win the first and second challenges to clear the danger.
Benfica's passing in the final third of the pitch just hasn't been good enough. We haven't seen much of Matic, Gaitan or Lima since the hosts fell behind.
Olympiacos are playing with great confidence in midfield and they're moving the ball about well. Unfortunately, the weather is beginning to have an impact on how quickly the ball is rolling across the pitch.
YELLOW CARD! Weiss pulls back Matic in midfield and he goes into the book for the blatant foul.
John drifts out to the left to collect the ball but he's quickly hunted down by a couple of visiting defenders. Benfica struggling to create anything at the moment.
There are some parts of the pitch where the water is beginning to settle now. The ground staff will have the opportunity to do their best to improve conditions at the break. Keep your fingers crossed.
HALF-TIME: BENFICA 0-1 OLYMPIACOS
The Benfica supporters have allowed their frustration to be heard as both side walk off the pitch. Olympiacos will be delighted with their first half display. Benfica's key men just haven't turned up yet tonight.
Benfica started the better of the two sides but they've been very poor for most of the first half. Dominguez and Weiss have linked well with Mitroglou, who is asking plenty of questions in attack.
Looking back at the goal, Garay hardly covered himself in glory after Dominguez collected the ball but some of the build up play was beautiful from the visitors.
Let's hope that the ground staff have been able to somehow improve some areas of the pitch. The rain has been falling heavily for around 15 minutes and Lisbon has also had showers for most of the day.
To be honest, it doesn't look very good out there at the moment. Both teams are heading out of the tunnel but they've returned to a pitch which has deteriorated even further during the break.
SUBSTITUTION: John has been brought off at half time and Ivan Cavaleiro is his replacement.
The referee thinks the match can go on but I wouldn't be surprised if it will be postponed at some point. Benfica get the game back underway.
This is awful. I want to watch as much football as possible but the conditions look dangerous out the right now. Surely the referee must take some action. Gaitan breaks into the box but he falls over due to a massive puddle in the corner of the area.
Olympiacos decide to forget about the pitch and attempt a couple of much longer passes, which Benfica deal with.
Roberto is almost made to look a fool when the conditions make it almost impossible for him to clear the ball away from the danger zone.
SHOT! Lima is inches away from an equaliser when his free kick drifts just wide of the post. I'm not sure if the fans are very happy that the referee is allowing this game to go on either.
Benfica nearly make a breakthrough but Gaitan is once again not helped by the pitch. Lima is punished for a foul on Siovas, who takes a swim in the paddling pool inside the penalty area.
All jokes aside, there is a very real possibility one of the players can get hurt in conditions like this.
Mitroglou is almost gifted a goal when the ball stops on its way to Artur, who does well to prevent the striker from doubling his side's lead.
YELLOW CARD! Awful from Perez, who might be starting to get annoyed with the conditions. Salino is hurt by the challenge and the Benfica man is lucky not to be sent off.
SUBSTITUTIONS: Weiss heads off and he's replaced by Delvin N'Dinga.
Siqueira thinks he might have won a penalty when N'Dinga challenges him clumsily after the substitute had failed to guide the ball out of play for a goal kick.
CLOSE! Laughable scenes in Lisbon. Mitroglou finds himself in plenty of space inside the box and he slides the ball past Artur. However, the conditions prevent the ball from crossing the line. Unbelievable.
YELLOW CARD! Mitroglou, probably slightly annoyed that he didn't score a moment ago, is booked for a late challenge in midfield.
YELLOW CARD! Gaitan is the next player to be booked as he stops N'Dinga from launching a counter attack. The referee seems to be oblivious to what the conditions are doing to this game.
The rain has started to fall very heavily, again! There's not really a pattern of play from either side. It's chaos.
UEFA should be embarrassed tonight. The referee seems to be ignoring the conditions. Neither side are able to play the game that they want to right now.
Cardozo rattles the crossbar with a powerful effort but the referee decides that the striker committed a foul just moments earlier.
Gaitan has just attempted to burst into the Olympiacos box but the wet pitch causes him to leave the ball behind. The hosts are on top at the moment but they cannot keep the ball for long enough to create many opportunities.
SUBSTITUTION: Sambou Yatabaré is on for Olympiacos and he replaces Fuster, who has had a very good game tonight.
Lima latches onto a long ball and fires wide but the referee had already raised his flag. The puddles are continuing to cause problems for both sides.
Olympiacos have enjoyed a good spell in the last couple of minutes but they seem to be wary about committing too many players forward. I can't blame them as the conditions are worst close to their own penalty area.
Cardozo wins a free kick, which Gaitan delivers into the box. Roberto comes off his line to punch the ball clear and the visitors regain possession.
Mitroglou does well to avoid being called for off side but the pass to him is very, very poor and Olympiacos fail to break clear despite having three players in advanced positions.
There's a stoppage in the games as Manolas goes down holding his ankle. The stretcher comes on off but there's no substitution just yet.
The wet pitch causes the ball to stop, resulting in a tough tackle in midfield between Almeida and Samairis. I'm not sure why, but the referee decides to award Benfica a free kick. The visitors hold firm though and clear the danger.
Mitroglou is gifted plenty of space but his 25 yard effort sails over the crossbar.
Luisao does well to block an effort from Mitroglou before once again keeping the visitors out when N'Dinga advanced into the box.
DISALLOWED GOAL! Mitroglou heads the ball into the bottom corner superbly but he's correctly punished for being off side.
GOAL! BENFICA 1-1 OLYMPIACOS (CARDOZO)
The match is level but Olympiacos will be furious. Three officials can see the ball but they all somehow decide that Benfica should have a corner. Luisao wins a header from the following set piece and Cardozo taps in from close range. Terrible luck for the visitors.
SUBSTITUTIONS: Just before the goal, Amorim and Rodrigo came on to replace Gaitan and Perez. Five minutes left in this crazy game.
Olympiacos respond to the goal well but there's not much support for Dominguez in the final third of the pitch and Artur comes out of his goal to easily collect a hopeful cross.
The away side win a free kick in a good area but Holebas wastes the opportunity as his delivery drifts wide of the goal.
The fourth official confirms that three minutes of stoppage time will be played.
SHOT! Olympiacos commit more players forward in stoppage time and the ball drops to Holebas, who fires over from 30 yards. That's a waste.
PENALTY APPEAL! Cardozo is convinced that he's been pushed inside the box but the referee ignores the protests and Olympiacos clear.
FULL-TIME: BENFICA 1-1 OLYMPIACOS
The referee brings an end to a game which has been entertaining for a number of different reasons. Olympiacos took the lead thanks to Dominguez but Benfica fought back to snatch a controversial late equaliser through Cardozo.
Many people, including yours truly, will claim that the game should have been abandoned early in the second half when heavy rain was making it almost impossible for the players but in the end both sides might be happy with a point.
PSG are even closer to securing top spot in the group thanks to a 5-0 victory over Anderlecht in Group C's other match tonight. Benfica and Olympiacos both have four points at the midway point and they'll meet again in Greece in a fortnight.
Thanks for joining me tonight and make sure you stick around on Sports Mole for reaction from across Europe. Goodnight.
