Olympiakos Piraeus named Takis Lemonis as coach on Monday in place of Besnik Hasi who left the club after three months in charge following the 3-2 defeat by fierce rival AEK on Sunday.
The Greek champion, who travels to Juventus on Wednesday in the Champions League, let a 2-0 lead slip in the Super League match at the Olympic Stadium and is now five points behind league leader AEK.
“Olympiakos FC announces the start of its co-operation with the coach Takis Lemonis,” the club said in a statement on its website.
Albanian-Kosovan Hasi was appointed in June, but a 3-2 home defeat by Sporting Lisbon in the opening Champions League group fixture and eight points from the first five league matches lost the 45-year-old the support of the Olympiakos hierarchy.
Lemonis, 57, returns for his fourth spell at the club having served as interim coach last season following the departure of Portuguese Paulo Bento.
The Greek will be assisted by former Olympiakos midfielder Christos Kontis.
The duo’s first task will be to revive the club’s slim Champions League hopes against the Italian champion. It faces a tough trip to La Liga leaders Barcelona next month.