Despite dominating the Greek home team, it was last season's Champions League second Tottenham who took the lead in the first half at Karaiskakis Stadium in Piraeus.
Harry Kane showed the way for the English to send in a penalty 25 minutes into the match, which was easily extended by 2-0 when Lucas Moura knocked the ball hard into the net.
However, Olympiakos, fueled by a hot-headed home crowd, did not give up and received an important reduction just before half time through Portuguese Daniel Podence.
The foreplay stood for French veteran Mathieu Valbuena - and likewise the subsequent receipt target. After 52 minutes, Tottenham's Jan Vertonghen fell awkwardly, but was determined to stay in the match.
Valbuena rose from the grass, shook off the pain - and put the ball into the net to the right of his compatriot in the goal, Hugo Lloris.
Despite chances on both sides in the final stage of the match, there were no more goals - and thus Tottenham had to settle for “only” one stick despite the lead with two goals.
At the same time, Club Bruges-Galatasaray played 0-0 in Belgium.