A 10-minute blackout in the Olympiakos attack in the second half put at risk the unbeaten record of the European champion this year, but the Reds ensured that the first visit by Bayern Munich to Piraeus for the Euroleague would end in defeat, by 88-83, on Thursday.
The Reds had the upper hand until the end of the third period, when Bayern drew level at 66-66 thanks to 15 unanswered points. The Germans went on to stretch the partial score to 25-5 and lead 76-71 five minutes from the end.
However, Olympiakos came back to lead 83-76 with 12 points in a row into the last minute and hold on to win despite making just eight out of 16 free throws in the last period.
This was the third victory for Olympiakos in as many games, putting it firmly on the driving seat of the group.
Bryant Dunston led the scoring with 19 points for Olympiakos, while Matt Lojeski added another 17.
In the Eurocup on Wednesday both Greek teams suffered shock home defeats, as PAOK lost 77-75 to Ankara and Panionios went down 91-86 to Lithuania’s Neptunas.