"Genoa CFC announce that Patrick Vieira is no longer first team coach... the first team has been entrusted on an interim basis to Roberto Murgita, assisted by (former Genoa player) Domenico Criscito," the club said in a statement.
Genoa have just three points and no wins from their first nine games of the season, their worst-ever start to a campaign in Italy's top flight.
Fans loudly protested against the team and club during Wednesday's 2-0 home defeat at the hands of Cremonese, after which Vieira was rumoured to be on his way out.
On Friday, Genoa sacked sporting director Marco Ottolini and had intended to keep on Vieira, who was hired in November and kept the club in Serie A with a mid-table finish.
However, widespread reports say that it was Vieira who decided to step aside, leading to Genoa bringing in Murgita and Criscito, the latter a fan favourite in his playing days who was in charge of the under-17 team.
Vieira is the second coach to lose his job in Serie A this season, after Igor Tudor was sacked by Juventus on Monday.
