Mercedes’ George Russell completed a clean sweep of Friday’s two practice sessions at the Sakhir Grand Prix as he subbed for Lewis Hamilton.
Russell beat Red Bull’s Max Verstappen by 0.128 seconds with the second Mercedes of Valtteri Bottas 11th.
The Finn set the fastest lap of the session, just under 0.2secs quicker than Russell, but had the time deleted for exceeding track limits.
Racing Point’s Sergio Perez was third ahead of Renault’s Esteban Ocon.
It was a highly accomplished performance from Russell, 22, in a car he had not driven before after being drafted in following Hamilton testing positive for coronavirus.
Bottas appeared to have a little pace in hand over the Briton but was visibly more on edge, especially through the bumpy middle sector of the new, shorter layout of Bahrain’s F1 track that is being used for the first time this weekend.
It was in that sector that Bottas made his error, sliding slightly wide through Turn Eight and having his time ruled out.
Russell also set the pace in the first session, when Bottas damaged his car early on running over a kerb, also at Turn Eight.
On race pace on the soft tyre, Russell appeared to be suffering greater tyre degradation but the two were closely matched on the hard tyre which will likely be favoured in the race.
Bottas also had two slight off-track moments on his race runs, sliding wide in Turns Five and Six.
Red Bull’s Alexander Albon was fifth fastest, ahead of Alpha Tauri’s Daniil Kvyat, the second Racing Point of Lance Stroll, Renault’s Daniel Ricciardo, Alpha Tauri’s Pierre Gasly and McLaren’s Carlos Sainz.
Ferrari had a desperate session. Sebastian Vettel had two spins and managed only 16th fastest time, while Charles Leclerc had a driveshaft fail after going over a kerb on the exit of Turn Eight early in the session and could not get out again. He was last without setting a time.