Olympiakos narrowly beat Panetolikos away to remain at the top of the Super League table, one point ahead of AEK that downed Aris at home.
The champion won 2-1 at Agrinio on Saturday thanks to a second-half penalty kick by Youssef El-Arabi, after Tiquinho Soares had given the Reds the lead and Nikos Vergos equalized for Panetolikos.
Olympiakos is now on 20 points, with AEK on 19 thanks to its 2-1 defeat of Aris in Athens on Sunday. Simos Mitoglou and Petros Mantalos were on target for AEK, with Mateo Garcia pulling one back for the Thessaloniki team.
PAOK, on 16 points, eclipsed Apollon Smyrnis 4-1 on Saturday, with two spots kicks, by Stefan Schwab and Douglas Augusto, plus strikes by Karol Swiderski and Giannis Michalidis. Giorgos Pamlidis had equalized for Apollon.
Panathinaikos could not beat the OFI defense at home, with the two teams sharing a goalless draw in the end. The Greens are fifth, nine points off the pace.
In other games, PAS Giannina drew 1-1 with Asteras Tripolis, and host Lamia denied Atromitos its first win of the season, equalizing twice for a 2-2 result.
On Monday Ionikos entertains Volos at Nikaia.