At the Parc des Princes, the current holders beat Barcelona 4-2 in a thrilling affair.
Desire Doue opened the scoring in the first half, before Xavi Espart equalized for Barca in the 55th minute.
Manchester City thrashed AEK Athens 5-1 and Liverpool came from two goals down to see off Villarreal 4-3.
Napoli also beat Bodo/Glimt 4-3, while Atletico Madrid played out a 1-1 draw at Stuttgart.
