Red Bull picked up at the Saudi Arabian Grand Prix where they left off in Bahrain two weeks ago by dominating first practice in Jeddah.
Max Verstappen set the pace, 0.489 seconds ahead of team-mate Sergio Perez, with Fernando Alonso’s Aston Martin third, 0.698secs off.
Alonso’s team-mate Lance Stroll was fourth fastest, ahead of the Mercedes of George Russell and Lewis Hamilton.
Ferrari’s Carlos Sainz was seventh ahead of Alpine’s Pierre Gasly.
Ferrari came into the weekend hoping they would be able to challenge Red Bull more closely than at the opening race, but that was not the case in the first session at least.
Sainz was 1.3secs slower than Verstappen and his team-mate Charles Leclerc was 11th fastest, 1.5secs off the pace.
Leclerc has a 10-place grid penalty for Sunday’s race after already exceeding his allocation of electronic control units because of two failures in Bahrain.
And during the first session they announced that they had also changed the engines on both cars “as a precaution” following Leclerc’s failure in Sakhir.
The session was held in daylight in the late afternoon, whereas qualifying and race are at night, so conditions will change in what should be a more representative second session at 17:00 GMT.
Despite his pace, Verstappen was complaining over the radio about understeer – a lack of front-end grip, which was also a problem for him in Bahrain, despite his domination of the race weekend.
And Hamilton, who announced before the session that he had split with his long-time trainer Angela Cullen, complained of a lack of grip as Mercedes lagged more than a second off Verstappen.