Two goals by Egyptian striker Ahmed Hassan and one by Portuguese midfielder Bruma steered Olympiakos to a 3-1 derby win over Panathinaikos on Sunday and a 46th Greek Super League title.
The play-off victory by the Piraeus club gives them an insurmountable 76 points, 22 points ahead of second-place Aris Thessaloniki with seven matches remaining.
Panathinaikos had taken a 1-0 lead in the 30th minute with a penalty by Italian forward Federico Macheda.
However, Hassan found the net in first-half stoppage time and struck again in the 72nd minute.
Bruma, on loan from PSV Eindhoven, added an insurance goal just before the final whistle.