The two incidents that led to red flags were crashes by Mercedes’ George Russell and Racing Bulls’ Liam Lawson.

Russell lost control on the entry to Turn 16, and nosed into the barriers, breaking his front wing. He missed the rest of the session because the car required a full system reset.

Lawson crashed on the exit of the same chicane, clouting the wall out of Turn 17, breaking his right-side wheels and coming to rest in the pit-lane entry.

Piastri looked and sounded confident as he returned to the track after his incident-strewn weekend in Baku, in which he crashed in practice and qualifying, jumped the start and then crashed on the first lap of the race.

He was making jokes about the Ferrari drivers getting in his way in the first session, saying: “I’m sure Ferrari will invent mirrors some day.”

And at the end of the second session he made a tongue-in-cheek remark about the driver cooling vest causing difficulties in the cockpit.

The disrupted session meant drivers did not have time to do their race-simulation runs at the end, so a clear indication of form did not emerge.

Alonso was quick all day in the Aston Martin on a track where the car’s weaknesses are not exposed and where he has always been strong.

But the team would be expected to slip down the field on Saturday.

His team-mate Lance Stroll was sixth fastest, 0.345secs off the Spaniard, followed by Haas driver Esteban Ocon, Williams’ Carlos Sainz and the Ferraris of Leclerc and Lewis Hamilton.