Force India’s Sergio Perez led the way during the opening practice session for the Italian Grand Prix, which took place in wet-but-drying conditions.
Heavy rain deluged the Monza region in the build-up to the 90-minute session, with torrents of water forming in the area, forcing the preceding GP3 session to be cancelled with no running having taken place.
The circuit had drained sufficiently for the session to begin on time, with the initial laps taking place on Pirelli’s Full Wet tyres.
Intermediates were used for the bulk of the session, with the best of the track conditions coming in the closing minutes, as the rain abated.
The circuit nonetheless remained sufficiently slippery to ensure that no-one ran slick rubber.
Perez held fourth place but vaulted to the front with a lap of 1:34.000 that left him 0.550s clear of Ferrari’s Kimi Raikkonen.
Perez’s Force India team-mate Esteban Ocon was third, in front of Brendon Hartley and Daniel Ricciardo, who recovered from an early power unit issue that briefly halted his car at Lesmo.
Ricciardo is running Renault’s updated C-Spec power unit, the only driver within the manufacturer’s set-up to do so.
Pierre Gasly placed sixth, in front of Max Verstappen, who encountered the only major drama in the session when he spun through Parabolica, though remained sufficiently clear of the barriers.
Renault duo Carlos Sainz Jr. and Nico Hulkenberg placed eighth and ninth respectively, with Valtteri Bottas rounding out the top 10 for Mercedes.
Title rivals Lewis Hamilton and Sebastian Vettel completed just 10 laps between them as they placed 11th and 17th respectively.
Vettel sat out most of the session after Ferrari detected a problem with the spare gearbox in his SF71-H.
McLaren reserve driver Lando Norris had his second FP1 outing in as many weeks and finished at the rear of the 20-car field, eight-tenths of a second behind Fernando Alonso.
