PIRAEUS, Greece, Jan. 8 (Xinhua) -- Olympiacos Piraeus upset Kirolbet Baskonia Vitoria-Gasteiz 91-87 after overtime here on Tuesday night and kept its hope alive for the fourth position of the EuroLeague regular season.

Baskonia enjoyed the lead at the beginning of the fourth period. They took great advantage of the absence of Olympiacos' Nikola Milutinov. But the team from Greece caught up and overtook the Spanish team in the end.

On Thursday, Olympiacos will travel to Madrid to face Real Madrid and Baskonia will welcome Gran Canaria at home in Vitoria.