Last season's beaten finalists Juventus opened their Champions League campaign with a scrappy 2-1 win over Galatasaray. Alessandro del Piero put the home side ahead after just five minutes, with Hakan Sukur levelling for the Turks 15 minutes later.
But veteran defender Ciro Ferrara scored the winner from close-range after 73 minutes.
In the other Group D match, Real Sociedad edged past Olympiakos courtesy of a late Darko Kovacevic penalty.
The other Spanish side in action on Wednesday, Deportivo La Coruna, were also taking on Greek opposition as they travelled to Athens.
And they too looked to heading for a 1-0 win when Walter Pandiani gave them a 12th-minute lead.
But AEK hit back to grab a point through Vassilis Tsartas five minutes from the end of normal time.
Also in Group C, Monaco survived a late fightback from PSV Eindhoven to win 2-1 in Holland.
 Sander Westerveld celebrates Real Sociedad's win over Olympiakos |
On-loan Real Madrid striker Fernando Morientes headed the visitors into the lead after half an hour and they doubled their advantage through Edouard Cisse's precise finish after 55 minutes.
Wilfred Bouma pulled one back for PSV with a stunning free-kick, but Monaco held on to take the points.
In Group B, Diogo Rincon came off the bench to score twice in the last 10 minutes to give Ukrainian side Dynamo Kiev a 2-0 win over Russian rivals Lokomotiv Moscow.
The Brazilian headed home Valentin Belkevich's cross to put the hosts ahead after 83 minutes and he doubled Kiev's advantage when he latched onto another ball from Belkevich and drilled a low shot into the corner.
Inter Milan ran riot in the other game in the group, thrashing Premiership leaders Arsenal 3-0 at Highbury.
All Inter's goals came in the first half with Julio Ricardo Cruz, Andy Van Der Meyde and Obafemi Martins finding the target. Thierry Henry missed a penalty for the Londoners.
A 26th-minute penalty from Juninho Pernambucano gave French side Lyon a 1-0 win over Belgian rivals Anderlecht in Group A.
And Bayern Munich fought back from trailing to a 57th-minute Alan Thompson goal to beat Celtic 2-1, with Roy Makaay getting both the goals for the German giants.