Olympiakos beat AEK 3-2 at the Olympic Stadium of Athens on Sunday and has opened a six-point gap at the top of the Super League table, given also the loss of PAOK at bottom team Atromitos.
The Reds were more efficient in attack at the top-of-the-table clash and scored from the first minute with Aguibou Camara. Sergio Araujo equalized for AEK, but two goals by Youssef El-Arabi took the game beyond the hosts, who only reduced their arrears with Araujo again.
Olympiakos is on 26 points and AEK on 20, while PAOK stayed on 19 after going down 2-0 at Atromitos due to a brace from former PAOK striker Efthymis Koulouris.
PAS Giannina produced a huge upset by demolishing host Aris 5-0 at the Kleanthis Vikelidis stadium, to climb up to fourth on 16 points.
OFI is on 15 with a 2-0 win on Saturday at Volos, where on Monday Panathinaikos produced its first away win as it came from behind to beat Lamia 3-1. Lamia led with Bachana Arabuli, but in the second half the Greens scored with Ramon Pascal Lundqvist, Federico Macheda and Mauricio to win the game that was moved from the Lamia stadium to Panthessaliko.
In other weekend games, Ionikos drew 1-1 with Asteras Tripolis and Panetolikos saw off Apollon Smyrnis 1-0.