Montenegrin teenager Stevan Jovetic struck twice in a 10-minute first-half spell to stun Liverpool in their Champions League Group E clash against Fiorentina.
The 19-year-old grabbed his first after 27 minutes after being put clean through, and then he touched home his second from the near post 10 minutes later.
Robin van Persie and Andrei Arshavin rescued Arsenal from a frustrating evening against Olympiakos and gave Arsene Wenger an early celebration to his 13th anniversary as manager this week.
It looked likely that Wenger's men would be punished for failing to convert their chances - a problem that has contributed to five years without a trophy - but Van Persie's second strike in four days gave them the breakthrough, before Arshavin added the second with a cheeky backheel.
Rangers crashed to a heavy 4-1 defeat to Sevilla in the Champions League amid controversy at Ibrox. The Scottish champions were denied a penalty late in the first half before Abdoulay Konko, the player responsible for the foul, set the ball rolling on an emphatic win for the La Liga side.
He grabbed the opener shortly after the restart, before Adriano, Luis Fabiano and Frederic Kanoute all helped themselves to a goal apiece as Rangers collapsed in the second half. Substitute Nacho Novo did pull a goal back late on but it was scant consolation for Walter Smith's men.
Lionel Messi and Pedro struck in each half to give holders Barcelona a 2-0 win over Dynamo Kiev in their Champions League Group F match.
Zlatan Ibrahimovic caused the Dynamo defence some early problems but it was Messi who opened the scoring in the 25th minute when he cut in from the right and struck a low shot that had enough power to beat Olexandr Shovkovskiy.
The Argentina forward had several chances to double Barca's lead before Pedro picked up Ibrahimovic's pass in the 76th minute and sent a precise shot into the bottom left corner.
Champions League debutants Unirea Urziceni held VfB Stuttgart to a 1-1 draw in their Group G encounter to earn their first point in the European competition.
Serdar Tasci fired Stuttgart ahead after five minutes but the Romanian champions equalised three minutes after half-time when midfielder Dacian Varga curled a shot past keeper Jens Lehmann.
Olympique Lyon ruthlessly crushed Hungary's Debrecen 4-0 to maintain their winning start in Group E.
Lyon took an early lead when Swedish midfielder Kim Kallstrom volleyed the ball into the right side of the net, then Miralem Pjanic curled in a delightful free-kick and 11 minutes later he crossed for Sidney Govou's header to make it 3-0. Bafetimbi Gomis scored the fourth with a brilliant lob six minutes after the break.
AZ Alkmaar were denied a first ever win in the group stages of the Champions League as Moussa Traore's last-gasp strike salvaged a point for Standard Liege at DSB Stadion.
The Dutch champions looked set to profit fully from Mounir El Hamdaoui's strike early in the second period of the Group H clash, but the three points were snatched from the grasp of coach Ronald Koeman a minute into stoppage time as Traore pounced.
In the early kick-off Inter Milan were held to a surprise 1-1 draw at Rubin Kazan in the Champions League but the Italian champions will be relieved to escape Russia with a point after ending the game with 10 men.
Rubin took the lead in the 11th minute thanks to Alejandro Dominguez but the hosts gifted Dejan Stankovic the equaliser on the half hour. Rubin were somewhat unfortunate not to take all three points after playing out the final half hour at a feverish pace following the dismissal of Mario Balotelli for a second bookable offence.