Mercedes driver Valtteri Bottas wrapped up practice for the first Tuscan Grand Prix at Mugello on Saturday with the fastest time for the third session in a row.
The Finn completed his sweep by lapping the fast Ferrari-owned Italian track with a best time of one minute 16.530 seconds on soft tyres.
Red Bull's Max Verstappen was just 0.017 slower and looking like a threat for qualifying even though Mercedes have so far taken every pole position this year.
Bottas's team mate and six times world champion Lewis Hamilton, who is 47 points clear in the standings after eight races, was third fastest, with Canadian Lance Stroll fourth for Racing Point.
AlphaTauri's Pierre Gasly, surprise winner at Monza last weekend on a podium without the usual three top teams, was fifth fastest.
Charles Leclerc, seventh fastest, was the leading Ferrari ahead of the team's landmark 1,000th championship grand prix, with team mate Sebastian Vettel 18th.
George Russell failed to set a lap time in his Williams after suffering an apparent brake failure early on.
(Reporting by Alan Baldwin; Editing by Alexander Smith)
