Last Updated: 23/10/12 8:18am
What a way to wrap up the game. Ramsey collects the ball from Giroud's flick on and neatly chips the ball over Megyeri to complete victory for the Gunners.
Coquelin goes down in agony in a collision with Abdoun and the midfielder cobbles to the side for treatment.
The corner falls to Ramsey, who takes a touch but then ends up firing spectacularly wide. If they can hold on to this it really will be a hard-earned victory for Arsenal.
Great chance for Arsenal! Cazorla is the architect as Giroud's luck continues to elude him as his thunderous drive clips Manolas' shoulder and zips wide.
Walcott tries but can't feed through Giroud as Manolas gets in the way. The substitute has really impressed since his arrival.
Maniatis' touch deserts him as he concedes the ball to Jenkinson. He charges down the right but loses out to Holebas and ends up conceding a foul as a result.
The offside flag catches Giroud out as Vermaelen takes another risk by charging forward and leaving his defence weakened as a result.
Cazorla, who has really picked up this half, makes a timely tackle of Fuster, as the game becomes far more open with less than seven minutes to go.
Lovely work from Abdoun is helped by Jenkinson's indecision. He fires straight at Mannone though before Walcott's run downn the other end lands in Megyeri's arms as Giroud lurked.
Ramsey goes in on Ibagaza but despite the playmaker's attempts for sympathy, a free-kick is given and he is told to get up.
Double change for Arsenal as goalscorer Gervinho comes off for Giroud, while Podolski is replaced by Ramsey.
Koscielny knocks the ball on from the corner but it seems to come off his shoulder and that makes it easy for Megyeri to gather.
Gervinho's shocker of a first touch lets him down after Gibbs' good ball down the left, much to Olympiacos' relief as he knocks the ball out of play.
Fuster falls in the area but a penalty would certainly have been harsh on Vermaelen. Arsenal then break and it's that man Vermaelen who storms forward and nearly has the chance to shoot before Megyeri claims.
Koscielny's first job against Ibagaza is to block his shot, which he does well, before Machado concedes a foul on Cazorla.
Machado pulls the strings down the left, making a crafty run through the centre but he just can't find the net tonight as his shot flies wayward.
Diakite shows strength to lead the attack for the hosts but Arsenal defend well as Jenkinson clears the lines.
Gervinho is penalised for presumably an offside after there was some tussling between him and Contreras - a battle that has been delightful to watch all night.
The short corner falls to Machado who just can't get a break with his shooting boots as his rifled effort clips an Arsenal defender and lands in the grateful arms of Mannone.
Chamberlain runs with Holebas and in the end it's excellent defending as the Arsenal man is nudged off the ball.
Chamberlain's free-kick finds Koscielny lurking but he can only head over the bar after losing his marker. Arsenal are very much on top of things now.
Koscielny stretches to hack away Siovas' chip over the top, before Contreras picks up a booking for a cynical tackle on Chamberlain.
Chamberlain gets down the right and collects from Jenkinson. In the end the attack is switched to the left and Olympiacos pile back to defend their goal.
Mitroglou goes for the top corner but it's not his best effort and it flies over to the right of Mannone's goal.
Gervinho is at the heart of everything good Arsenal do at the moment. He plays in Chamberlain who dances across the box before a precise tackle from Contreras ends the danger.
It's all Arsenal now, as Podolski sets free Gervinho who is someway offside after tracking back from the Gunners' last attack.
It's not a moment of glory again for Megyeri, but after brilliant work from Gervinho, he cuts back to Podolski who buries a shot away which fires through the keeper's legs to give Arsenal the lead!
Mitroglou goes for the spectacular with a wild shot from range which in the end is not far out from giving Mannone a heck of a save to make.
Koscielny heads away and Gervinho breaks excellently. His options eventually run out though and Siovas regains control.
Machado is the man to take a high boot this time, as Coquelin concedes a free-kick roughly 35 yards out.
Gervinho is caught offside rather unluckily from Gibbs' ball, with Arsenal starting brightly since the break.
Gibbs continues to be the catalyst in everything good Arsenal do. Cazorla's tackle on Diakite is well timed but ends up with the visitors having a throw-in.
Siovas nearly kicks Cazorla's head off with a high boot. Arsenal play the free-kick quickly and Cazorla, back on his feet, fires wide from Gervinho's precise pass.
Coquelin's ball out for Cazorla is a yard ahead of the midfielder, who continues to endure a frustrating evening thus far.
Mitroglou charges through Coquelin, a free-kick surely, but the referee waves play on and in the end at least Arsenal win a throw-in.
Gibbs makes wonderful progress down the right to link up with Cazorla. He gets his shot all wrong though and scuffs it wide from 20 yards.
Wow. A tepid opening 40 minutes explodes into life with two goals in three minutes. Send your second half predictions to email@example.com
Incredible scenes! Greco's sweet ball from the left is glanced into the far corner by Mitroglou and Olympiacos are deservedly level.
Olympiacos are unlucky to be behind truth to be told - and as replays show Megyeri got down rather slowly to Gervinho's effort, they'll feel slightly more aggreieved. Vermaelen, meanwhile, has another horror show as his error allows Machado in but he fires straight at Mannone.
It's lovely work from Gervinho, who picks up the ball up after Gibbs' pass took a touch off Contreras, before firing nearly past Megyeri to give the Gunners the lead!
Mitroglou and Koscielnt collide, with the striker ajudged to have been the guilty party and Arsenal win the free-kick.
Machado again takes the free-kick and that may be his last as he curls the ball straight into Mannone's arms.
Coquelin is caught out as Siovas makes the tackle. Moments later, Vermaelen sloppily floors Machado and concedes a free-kick from 25 yards.
Arteta plays in Jenkinson but eventually, as is the pattern of the first half, Arsenal are forced into retreat mode before Gervinho's attempted flick results in the loss of possession.
Golden chance for Olympiacos! Maniatis does brilliantly to whip the ball in from the right and Mitroglou incredibly blazes the ball wide from close range.
Holebas takes a tumble under Jenkinson but no foul is given and Arsenal break. Strong defending from Contreras on Gervinho ends that attack though.
Good work from Gervinho earns Arsenal a corner. Cazorla whips in the delivery but Koscielny's header sees the ball travel behind him.
Chamberlain picks up the ball from a loose Siovas pass but the visitors' tactics are really terrific as they continue to restrict Arsenal's movement going forward.
Best chance of the game falls to Olympiacos as Machado keeps the ball alive before Fuster's deflected shot forces an impressive save out of Mannone.
Vermaelen, playing more as an attacking midfielder makes another surging run before eventually losing out, with Koscielny sliding through Fuster to earn a booking.
Gervinho and the Arsenal faithful claim a penalty as the ball hits Contreras' arm. A decision would have been harsh though as no man on earth could have surely avoided the contact.
Podolski breaks away down the left but a well timed tackle from Diakite halts his movement and again forces Arsenal's movement backwards rather than forwards.
Gervinho shows good movement to meet Chamberlain's pass. The return ball catches the winger unaware though as it rolls out of play.
Vermaelen charged like a bull at the corner and is penalised for his enthusiasm for a heck of a lunge on Contreras.
Gibbs keeps Coquelin's pass in splendidly at the byline, with Arsenal winning a corner as a result of his work.
Greco takes a clip as Cazorla's knee clobbers him in the head. The winger has stayed down while the visitors wait to take their resulting free-kick.
Arsenal probe Olympiacos' half until Gervinho loses out to Manolas. The visitors press forward on the attack with Mitroglou's header watched all the way by Mannone.
Cazorla's quick feet earn Arsenal a free-kick after the maestro dispossessed Machado down the right. Koscielny can't find Gervinho with his sprayed ball though as Contreras collects.
Gervinho skips across the turf to beat Contreras to the punch, with Arsenal winning a throw-in for the striker's troubles.
Arteta plays an uncharacteristically dreadful pass out to Chamberlain as Olympiacos win back possession in Arsenal's half.
Maniatis takes a knee to the back of the head from Gibbs and while a little woozy, the midfielder should be fine to continue.
Olympiacos work the ball around sweetly, but Gibbs closes down Maniatis brilliantly to forces the visitors back.
Olympiacos earn a respite when a Gibbs throw-in gets knocked back out of play off the left-back. A really strong start for the Gunners so far.
A wonderful strike from Cazorla forces a top save from Megyeri as the keeper tips over the effort to concede another corner.
Gibbs and Podolski link up to good effect as the left-back skips past Diakite before winning a free-kick on the edge of the penalty area.
Slovas is forced to clear from a second delivery by Chamberlain but Arsenal continue their onslaught as Contreras clears wildly to concede a throw-in.
Jenkinson powers forward and his drilled delivery ends up being cleared behind by Contreras for the first corner of the match.
Cazorla crosses from the right this time, exploiting further poor defending but Podolski can't battle past Diakite and Megyeri claims again.
Superb work from Chamberlain sees him dispossess Holebas down the right but his cross into the box ends up with Megyeri after solid defending from Manolas.
Machado is presented with a second chance to strike but his speculative half-volley from the corner trickles wide.
A shocking misunderstanding between Mannone and Vermaelen nearly sees the Gunners pay but Vermaelen gets back to concede a corner from David Fuster's shot.
Jenkinson is unhappy as a tug on Mitroglou is punished by the referee. The free-kick from Machado is some way wide to the Arsenal defender's relief though.
Vermaelen takes a crunching under Holebas as the Gunners win a free-kick just inside Olympiacos' half.
Arsenal keep possession neatly, but the visitors stay organised as they restrict the movement of the Gunners from reaching their half.
Nishan Sharma writes: "Always have to track the CL while at work here in Calgary. Oh well - at least it's a *good* distraction. I think co-workers are on to me, as I wore my scarf today. Love that a strong squad has been named...go on you Gunners - get that momentum back! Prediction: 3-1."
Lee Drury predicts: "I think its going to be a good game tonight ill be following closely, I have a good feeling Giroud can come off the bench and make a real difference, 3-1 to the gooners!"
Analysing the team news further, Arsenal bring in Alex Oxlade-Chamberlain and Francis Coquelin back into the side. Gervinho again starts down the middle, so Theo Walcott was on the bench as the Gunners look to recover from Saturday's Barclays Premier League defeat by Chelsea. Steve Bould coaches the side with manager Arsene Wenger serving the second of his European touchline bans. Kostas Manolas leads the attack for their Greek opponents, while former Manchester United goalkeeper Roy Carroll is among the substitutes.
Olympiacos: Megyeri, Diakite, Manolas, Contreras, Holebas, Siovas, Maniatis, Greco, David Fuster, Paulo Machado, Mitroglou. Subs: Carroll, Modesto, Ibagaza, Pantelic, Lykogiannis, Diogo, Abdoun.
Arsenal: Mannone, Jenkinson, Koscielny, Vermaelen, Gibbs, Arteta, Cazorla, Coquelin, Oxlade-Chamberlain, Gervinho, Podolski. Subs: Shea, Andre Santos, Giroud, Walcott, Ramsey, Djourou, Arshavin.
Liam is: "Here in Waterford, Ireland - studying for my ACCA F5 exams, whilst having a sneaky eye on the Arsenal game - hoping for a much improved performance from Saturday - 3-0 to the Arsenal I hope!!"
Good evening and welcome to the Emirates Stadium for Arsenal v Olympiacos in their Champions League Group B clash. The teams will be uploaded shortly, if you'd like to drop me a line in the meantime you can send an e-mail to firstname.lastname@example.org