Olympiacos moved three points clear at the top of the Greek Super League as Dudu's winner earned them a 2-1 victory over Ergotelis.
Giorgi Shashiashvili gave the visitors the lead in the 22nd minute, but Kostas Mitroglou levelled seven minutes before half-time.
And Dudu sealed a seventh win in eight games for Olympiacos as they moved clear of second-placed Panathinaikos, who have a game in hand.
Panionios came from behind to beat Giannina 3-1, Fanouris Gound! oulakis (17), Bosko Balaban (23) and Carlos Castiglione (72) scoring after Patrick Dimbala had given Giannina a 15th-minute lead.
Atromitos were 2-1 winners at Asteras Tripoli, Elias Anastasakos (31) and Emanuel Perrone (43) putting the visitors two up before Vangelis Kaounos pulled one back in the 82nd minute.
