Olympiakos beat Group F winners Arsenal 3-1 here on Tuesday but failed to qualify for the last 16 of the Champions League following Marseille's victory over Dortmund.
It was a heartbreaking evening for the Greek side who, having scored their third goal with a minute left, heard that Marseille, who netted in the 85th and 87th minutes, had overturned a 2-0 deficit to win 3-2 in Germany.
First-half goals from Rafik Djebbour and David Fuster gave Olympiakos a 2-0 lead at the break before Yossi Benayoun pulled one back for the Gunners.
But in the 89th minute Olympiakos sealed victory when, from a corner, former Aston Villa defender Olof Mellberg's header hit the post and Francois Modesto followed up to score.
Arsenal kicked off knowing they alone among English clubs had already qualified for the last 16, regardless of the result of their final group stage clash.
Gunners' boss Arsene Wenger selected a second string side in what was the Frenchman's 200th European tie as a manager.
Lukasz Fabianski came into goal, behind a back four of Johan Djourou, Thomas Vermaelen, Sebastien Squillaci and Andre Santos.
Emmanuel Frimpong, 19, and Francis Coquelin, 20, also started, as did England Under-21 international Alex Oxlade-Chamberlain, with experienced Israel international Benayoun playing just behind Andrey Arshavin and Marouane Chamakh.
"We must give credit to Olympiakos tonight because they played a very physical game and in the first half it was very difficult for us," Wenger told Sky Sports 2.
"And I don't think we had the right tactical approach.
"In the second half at 2-1 we looked like we might come back, but they were dangerous and probably deserved it.
"Many of the players did not have experience in the Champions League so were a bit surprised by the pace of the game."
Olympiakos welcomed back Mellberg from injury, with in-form striker Djebbour up front.
The hosts made a terrific start but Arsenal broke on the counter-attack only for Arshavin to shoot straight at Hungarian 'keeper Balazs Megyeri.
It was Olympiakos, though, who took a 16th-minute lead when Arshavin failed to respond to Fabianski's throw and the hosts regained possession, with Djebbour rounding the keeper and scoring from a tight angle.
Arsenal's defence were always the more vulnerable early on and a low cross from the left caused panic in the Londoners' penalty area, with Fabianski injuring his knee in the ensuing melee.
The Pole was carried off on a stretcher and replaced by 23-year-old Vito Mannone -- whose last appearance was on loan at Hull in April.
And Arsenal's new 'keeper helped gift Olympiakos a second goal in the 36th minute.
He initially responded well to head clear a dangerous ball on the edge of the area, but when Fuster lobbed the ball back into the area Mannone, who seemed to have lost his bearings, tried to scissor-kick clear, missed, and Olympiakos were 2-0 up.
Modesto might have made it 3-0 when, after another Mannone error, he somehow headed wide from just a few yards out.
"I think we didn't help our goalkeepers," insisted Wenger. "We exposed them with our lack of quality in the passes we gave them and they were quite brave."
Arsenal halved the hosts' lead in the 57th minute when Ignasi Miquel's cross was chested down by Chamakh and Benayoun lashed the ball home before Modesto added the hosts' third.