|Back: Wednesday saw Arsenal host Bayern again, after their thrilling tie last season.|
Two English sides were in action on the first week back in the UCL, with Manchester City losing 2-0 to Spanish giants Barcelona on Tuesday while Arsenal went head-to-head with German champions and defending UCL holders Bayern Munich at The Emirates on Wednesday night.
|Superior: Bayern have toppled rivals Dortmund, 17 points ahead of them in the Bundesliga.|
|Dominant: Bayern have only conceded 9 goals in the league this season, losing once in the CL|
|Impact signing: Ozil has scored 5 goals and made 10 assists this season.|
|Influence: Ozil has linked-up well with the rest of his new Arsenal team-mates|
|On-form: Giroud has scored 12 goals this season for Arsenal, making him reliable|
|Leadership: Flamini has made a significant impact on his Arsenal return, becoming the natural leader in midfield.|
|Flamini helps to solidify the Arsenal midfield, something they were lacking previously.|
|Top talent: Gotze plays an integral part in the Bayern side, making an impact after his summer move from Dortmund.|
|Gotze was one to watch as Bayern looked to beat Arsenal at The Emirates yesterday|
|Guardiola made sure he signed Thiago at Bayern ahead of a proposed move to United|
|Chopped: Ozil is clearly fouled by Boateng as he darts inside the box, giving away a penalty|
|Poorly executed: Ozil's run-up is all wrong as he sees his penalty saved (below)|
|Outstretched hand: Neuer does well to deny Ozil's penalty off balance on the ground.|
FACT: Mesut Ozil has missed his last three penalties.
Arjen Robben had a 20-yard effort well wide in the 10th minute as the visitors looked to try and compose themselves steadily into the game and test Szczesny more often..
Arsenal's English full-back Kieran Gibbs did well to defend on the flank against the advances of Gotze and Lahm until he limped off the pitch and had to be replaced by Monreal as a precaution for a suspected hamstring strain after 30 minutes.
|Bad news: Gibbs limped off the pitch after a suspected hamstring strain.|
Koscielny did well to obstruct Mandzukic's view of goal inside the box with a well-timed challenge, before Szczesny was sent off after an accidental collision with Robben inside the box with his trailing leg in the 39th minute.
Arsenal go down to ten men, with creative midfielder Cazorla being replaced by Fabianski as the whole complexity of the match changes completely (just like in the City match on Tuesday).
FACT: Szczesny's red card was Arsenal's 100th since Wenger was appointed manager over 15 years ago.
|Accidental: Szczesny was sent off for this challenge on Robben inside the box.|
|Contact but not deliberate: Szczesny clipped Robben's ankle as he tried to win the ball|
|Robben rolls on the floor after the tackle which looks worse on first viewing than when shown on the replay|
|Controversial: Szczesny was sent off by the referee, changing the match completely afterwards|
|Cazorla is replaced by Fabianski as The Gunners go down to ten, despite playing well.|
|Alaba has his penalty hit the post as both sides fail to take their chances in a dramatic first-half|
The German giants did just that, keeping up the pressure on their English counterparts and holding the ball up well looking for team-mates in space.
The famous quote says: "If your opponent doesn't have the ball, they can't score." and this is exactly what Bayern did in the second-half, fully in control and able to dictate the tempo of the match from slow to fast counter attacking movement in an instant - if it was not for the dogged performance of a clearly tired Arsenal side it could have easily been 5 or 6-0 at full-time.
Koscielny and Robben both had chances which narrowly missed the mark for either side within the first 10 minutes of play in the second-half, before a good passing move was clinically finished off by rumoured Manchester United target and German midfielder Toni Kroos who broke the deadlock with a drilled power strike in the 53rd minute, leaving Fabianski scrambling towards the top corner.
|Kroos hits his second longshot goal against Arsenal to make it 1-0 in the 53rd minute.|
|2 powerful: Kroos celebrates his power finish with his team-mates as Bayern took the lead|
Muller replaced Mandzukic in the 63rd minute as Guardiola and his men looked to close out the match in which they had been dominating since Szczesny's dismissal which was very harsh on Arsenal - who were playing very well up until the red card incident. Constant pressure from Bayern with rarely any mistakes on the ball passing-wise as Robben had another curling strike towards goal just wide, making Fabianski worried.
Wenger had to take a risk with his last substitution of the match (after being forced to make two early on) as he knew his players were getting very tired - so Oxlade-Chamberlain (who was one of the only bright sparks throughout the match for Arsenal) was replaced by midfielder Tomas Rosicky in an attempt to see out the match and hopefully equalise with just under 20 minutes to play.
|Handful: The Ox was creating chances out of nothing for Arsenal, a bright player throughout|
Thiago was replaced by Peruvian striker Claudio Pizarro in another attacking-minded switch for Bayern towards the end with just over 10 minutes to play as Arsenal make sure all their men are behind the ball defending - desperate not to concede again.
Bayern's captain, Full-back (and converted) defensive-midfielder Phillip Lahm split the Arsenal defence with an exquisite long ball past two defenders through towards Muller who was unmarked, heading past Fabianski who could only flap at the effort as it dropped past him into the net to double Bayern's lead with just minutes to play in the 88th minute.
|2-goal cushion: Muller heads past Fabianski, taking advantage of a good ball from Lahm.|
|Screaming with relief: Muller celebrates his headed finish past Fabianski to make it 2-0.|
The holders were more than comofrtable as Arsenal were unlucky to concede late on, seeing the match through with a few passes across the midfield to run down the clock and go back to Germany for the return leg with a comfortable 2-goal cushion.
|Loyal support: Bayern applaud the travelling fans after a 2-0 display at The Emirates,|
AC Milan 0 Atletico Madrid 1
A late headed goal from Brazillian striker Diego Costa in the 83rd minute gave Atletico Madrid a vital away goal in their Last 16 tie against Italian side Milan, who have lost their way in Europe in the last few years.
|Clinical: Costa broke the deadlock with minutes to spare as Atletico took a crucial away goal|
|Finisher: Costa celebrates his 5th goal in the CL this season, at a crucial time for his side.|
|Deadline day signing: Taarabt joined Milan on a loan deal at the end of the window|
|Straight into action: Taarabt played his first Champions League match against Atletico.|
|Quick dribbler: Taarabt was unable to help his side get back into the match and score|
|Defensive work: Taarabt (in red) does well to track back and tackle Insua on the counter|
|Rough ride: Balotelli had to be taken off after a painful collision.|
|Ouch: Balotelli clutches his shoulder after injuring it against Atletico|
|Key: Milan fans will be hoping he is fit for the second leg as they look to overturn a 1-0 deficit|
Tottenham Hotspur travel to Ukraine to play against Dnipro, whilst Swansea host a tough test in Serie A side Napoli.