Vassilis Torosidis headed home a second-half winner for Olympiacos who got their Champions League campaign off to a great start with a 1-0 victory at home to AZ Alkmaar.
The game had looked destined for a draw with neither side looking likely to break the deadlock.
But with 12 minutes remaining Torosidis rose unmarked in the visitors’ box to head home a cross from Jaouad Zairi from six yards.
Olympiacos came into the game having parted with manager Temuri Ketsbaia during the week and the hosts looked every inch a club in turmoil as they began the encounter in sluggish fashion.
Neither side looked capable of keeping possession for any length of time but the visitors at least showed flashes of a cutting edge in what was a drab first half.