Sergio Perez crashed his Red Bull at the famous Parabolica corner in Friday practice at the Italian Grand Prix.
It was the latest in a series of errors by the Mexican, whose hopes of a title challenge to team-mate Max Verstappen faded earlier this year.
Ferrari’s Carlos Sainz was fastest, by 0.019 seconds from McLaren’s Lando Norris, with Perez third.
Verstappen’s best lap was wrecked by traffic and he ended the session only fifth, behind McLaren’s Oscar Piastri.
Perez’s crash, from which he emerged unhurt and did only relatively light damage to his car considering the high speed at which he lost control, blotted what had otherwise been a strong day for him.
Perez was actually faster than Verstappen on the race-simulation runs in the last part of the session by about 0.1secs on average over the few laps they managed before the crash.
It was a strong day from Sainz, on his 29th birthday. He topped the second session after being second fastest, only 0.046secs behind Verstappen, in the earlier first hour.
His team-mate Charles Leclerc was sixth fastest in the second session, 0.361secs off the pace, and fourth quickest behind Perez in the first.
Williams driver Alex Albon was seventh fastest, followed by Aston Martin’s Fernando Alonso, Williams driver George Russell and the Haas drivers Nico Hulkenberg and Kevin Magnussen.
Lewis Hamilton was only 17th fastest, complaining that he was lacking speed on the straights after apparently choosing a higher-downforce set-up than Russell.
The seven-time champion asked to change his car during the session but was rebuffed by his race engineer Peter Bonnington, who said it would prevent them doing the running they needed.
Alonso’s team-mate Lance Stroll had a difficult day. He sat out the first session so reserve driver Felipe Drugovich could be given some mileage, and then his car broke down with a fuel-system problem on his first lap out of the pits.
It leaves the Canadian going into Saturday having done not a single flying lap.
