With reigning champions Panathinaikos suffering a shock 2-0 loss at Larissa and only five games left, Olympiakos can secure a 38th league title by winning at PAOK Salonika next weekend.
Olympiakos recorded their 12th home victory in a row with goals from Francois Modesto, Marco Pantelic and Kevin Mirallas in a rampant 20-minute spell after half-time.
The match against their Cretan opponents was played without any fans present as punishment for the pitch invasion following their 2-1 derby win over Panathinaikos two weeks ago.
"We know that everybody is saying we have already won the title but for us it is not this way," Olympiakos coach Ernesto Valverde told reporters.
"Titles are not won until the mathematics are taken care of. We still have tough games to go so we are not celebrating quite yet," he said ahead of next Sunday's trip to Salonika.
Olympiakos have a 100 percent home league record this season and need three more wins to set a club record by going unbeaten through a whole campaign at their Georgios Karaiskakis stadium.
They will have claimed 13 of the last 15 league titles if they wrap up this year's championship.
AEK Athens continued their run of good form with a 4-0 hammering of PAOK at the Olympic Stadium on Sunday to move up to third place, 11 points adrift of Panathinaikos.
Former Portsmouth midfielder Papa Bouba Diop put the Yellows ahead after 11 minutes, before Nacho Scocco netted twice and defender Trainos Dellas headed home in the closing stages.
Panionios came from behind to beat Atromitos 2-1 and move four points clear of the relegation zone while Larissa remain second-bottom five points from the safety zone.
