• The Williams' driver is standing-in for Lewis Hamilton who tested positive for Covid-19 earlier this week.
• The Sakhir GP takes place on the shorter outer track of the Bahrain Circuit.
• For more motoring stories, go to Wheels24.
George Russell looked perfectly at home in Lewis Hamilton's Mercedes during Friday's opening practice session for the Sakhir Grand Prix by going fastest on his debut as the seven-times Formula One champion's stand-in.
The 22-year-old, put in Hamilton's seat after his fellow Briton tested positive for Covid-19, set a time of 54.546 seconds as Formula One for the first time lapped around the shorter outer layout of the Bahrain International Circuit that hosted last Sunday's race.
Russell headed Max Verstappen and Alexander Albon who completed the top three in their Red Bulls.
Mercedes' Valtteri Bottas only managed fourth and was 0.322 seconds behind his substitute team mate's benchmark.
However, the Finn was nursing damage on his car.
Jump onboard with @GeorgeRussell63 in FP1 - as he powers around the new layout at Sakhir... in a Mercedes ????#SakhirGP ???? #F1 pic.twitter.com/dHqdWFjDBE— Formula 1 (@F1) December 4, 2020
"Valtteri broke his car pretty early on in the session," Mercedes team principal Toto Wolff told Sky Sports.
"He even stopped running.
"So we didn’t see Valtteri in the right car, but this is not to diminish George’s performance for a first time in the car, it's good."
Behind the top four, Russian Daniil Kvyat was fifth ahead of AlphaTauri team mate Pierre Gasly.
Esteban Ocon was seventh for Renault ahead of Ferrari's Sebastian Vettel and team mate Daniel Ricciardo.
Charles Leclerc in the other Ferrari rounded out the top 10.
Russell, whose is backed by Mercedes but had been placed at engine customer Williams to learn the ropes for the last two seasons, was not the only driver getting used to new surroundings.
Brazilian Pietro Fittipaldi is making his Formula One debut at Haas as stand-in for the injured Romain Grosjean.
Briton Jack Aitken, also a rookie, is filling Russell's seat at Williams.
The pair propped up the bottom of the timesheets.
FP1 CLASSIFICATION ??@GeorgeRussell63 tops an official race weekend session for the first time in his F1 career ??#SakhirGP ???? #F1 pic.twitter.com/0ON1IYUmg4— Formula 1 (@F1) December 4, 2020