Last season's runners-up Arsenal lost to CSKA 1-0 in their European Champions league Group G away game while the former champions Real Madrid, AC Milan and Manchester United scored wins on Tuesday.
Arsenal, who kept winning streak, succumbed to a goal from Daniel Carvalho who scored on a powerful free-kick in the 24th minute.
In the other Group G game, FC Porto claimed their first Champions League win of the season with a thumping 4-1 victory over SV Hamburg. Lisandro Lopez, Lucho Gonzalez and Helder Postiga put Porto in control before Piotr Trochowski's consolation.
Lyon maintained their perfect start in Group E with a 3-0 win over bottom side Dynamo Kiev - who are as good as out after losing their first three matches.
Juninho and Kim Kallstrom put Lyon ahead before half-time before Florent Malouda's header completed the scoring.
Real Madrid also impressed on the road, thrashing Steaua Bucharest 4-1.
Sergio Ramos, Raul and Robinho put Real in control and although Valentin Badea pulled one back, Ruud van Nistelrooy's neat chip made sure of victory.
Kenny Miller netted twice as Celtic took a huge step towards qualifying for the knockout stages for the first time with a convincing victory over Benfica.
Stephen Pearson rounded off the scoring to give his side a deserved 3-0 win.
Manchester United comfortably beat FC Copenhagen, with Paul Scholes, John O'Shea and Kieran Richardson all netting in a 3-0 win at Old Trafford.
If Celtic beat Benfica in Portugal in their next game and Manchester United draw in Denmark, both will progress.
AC Milan stayed top of Group H after Kaka's winner against Anderlecht.
Milan had Daniele Bonera sent off at the start of the second half but they responded well and Kaka smashed home a superb drive to give them the points.
Lille are in second place after they hit two late goals to see off winless AEK Athens 3-1.
Mathieu Robail put Lille ahead before Vladimir Ivic equalized - but Daniel Gygax and Jean Makoun scored in the last 10 minutes for the French side.
Source: Xinhua