Olympiakos came close to scoring a precious away win at Vitoria, but Caja Laboral managed to emerge unscathed from the match with an 81-79 victory for the Euroleague.
The Reds led throughout the first half (40-32 at half time) and stretched their lead to 12 points two minutes into the third period (49-37).
However Caja Laboral tightened up its defense from that point and improved its attack to get close to Olympiakos in the last period of the game and win it through a Pablo Prigioni basket 1.7 seconds from the end.
Vassilis Spanoulis led the scoring for Olympiakos with 19 points.
This was Olympiakos?s second loss in three games in the group.