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Moscow, Russia (SportsNetwork.com) - Manchester City's struggles in the Champions League continued on Tuesday as the club squandered a two-goal lead to settle for a 2-2 draw at CSKA Moscow.

City opened its European slate with a last-gasp defeat against Bayern Munich before being outplayed in a 1-1 draw with AS Roma at the Etihad last time out.

Things appeared to be getting better, though, as the Citizens climbed in front at the half-hour mark of Tuesday's clash when Edin Dzeko beat the offside trap and played a square pass for Sergio Aguero to tuck home with ease.

City extended the lead nine minutes later when a scuffed shot from Aguero fell kindly to James Milner, who was arriving at the back post to convert from close range.

The visitors were in cruise control until CSKA reclaimed some momentum in the 65th minute. A well-worked move culminated with Seydou Doumbia evading a sliding challenge from Pablo Zabaleta to fire home a low cross.

It appeared as if City had done enough to hold off the Russian club, but CSKA was awarded a dubious penalty in the 85th minute when Doumbia hit the turf theatrically under a challenge from Aleksander Kolarov. Bebras Natcho converted the ensuing attempt to bring the hosts level and leave City winless from its first three Champions League fixtures of the season.

In Group E's other fixture, Bayern Munich trounced AS Roma, 7-0, at the Stadio Olimpico.

Bayern produced five goals in the opening period as Arjen Robben got the visitors off the mark nine minutes in. That strike opened the floodgates as the German club netted four goals in the span of 11 minutes to put the match to bed.

Mario Gotze doubled Bayern's advantage in the 23rd minute before Robert Lewandowski extended the lead with a header in the 25th minute.

Robben added another at the half-hour mark while Thomas Muller's penalty in the 36th minute left Roma with no way back.

Gervinho salvaged a bit of pride for the Italian club by pulling back a consolation goal in the 66th, but goals from Franck Ribery and Xherdan Shaqiri in the 78th and 80th minutes, respectively, added insult to injury for Roma.

Bayern remains firmly atop the Group E table with nine points from three games. Roma sits second on four points followed closely by Manchester City on two points and CSKA on one point.

Barcelona got back to winning ways in Champions League action by claiming a 3-1 win over Ajax at Camp Nou on Tuesday.

The Catalans, who suffered a shock 3-2 defeat to PSG in their last European fixture, were in front after only seven minutes in Tuesday's affair as a dizzying passing sequence saw Lionel Messi thread the needle for Neymar, who curled a superb effort into the back of the net from the left flank.

Messi went from provider to scorer by taking a sublime through ball from Andres Iniesta in the 24th minute and slotting home a shot from close range to double Barcelona's advantage.

Ajax pulled one back through Anwar El-Ghazi in the 88th minute only to see youngster Sandro Ramirez restore Barcelona's two-goal lead shortly after.

PSG remained atop the Group F table as Edinson Cavani found the back of the net with a tame effort in the 87th minute at the GSP Stadium to give the Parisians a 1-0 victory over APOEL.

Chelsea scored three goals on either side of halftime to cruise to a 6-0 victory over Maribor at Stamford Bridge on Tuesday.

Loic Remy, Didier Drogba and John Terry found the back of the net in the opening period while an own goal from Mitja Viler and a brace from Eden Hazard after the interval concluded the home rout.

Also in Group G action on Tuesday, Eric Maxim Chupo-Moting converted a late penalty to give Schalke a dramatic 4-3 victory over Sporting Lisbon.

Rounding out Tuesday's Champions League slate, Luiz Adriano netted five goals, including two from the spot, to lift Shakhtar Donetsk to a comfortable 7-0 victory at BATE Borisov while Ricardo Quaresma provided a 75th-minute winner in FC Porto's 2-1 home defeat of Athletic Bilbao.