Manama, Bahrain: George Russell upstaged his Mercedes team-mate Valtteri Bottas and impressed everyone else on Friday when he topped the times in both sessions of a record-breaking day's practice at the Sakhir Grand Prix.
Substituting for coronavirus victim seven-time champion Lewis Hamilton, the 22-year-old Briton outpaced all of his rivals with a dazzling display of pace and poise on the high-speed short-lap 'outer loop' at the Bahrain International Circuit.
His time of just 54.713 seconds represented the briefest lap of the season and was well within the time set by Niki Lauda with the fastest lap pole time in Formula One, set at the 1974 French Grand Prix.
Russell was only released by Williams on Monday, but showed no sign of nerves in Hamilton's title-winning car, despite being notably taller than Hamilton and having to wear racing shoes a size smaller than usual to squeeze into the car.
He outpaced second-placed Max Verstappen of Red Bull by 0.323 seconds while Bottas struggled to deliver a clean timed lap and wound up down in 11th, his two best laps " both faster than Russell's " were eliminated because he exceeded track limits.
Sergio Perez was third for Racing Point ahead of Renault's Esteban Ocon, Alex Albon in the second Red Bull and Daniil Kvyat of Alpha Tauri with Lance Stroll seventh for Racing Point.
The session was run in warm and dry conditions without major incident under floodlights after nightfall. Despite his protests, Mercedes boss Toto Wolff had to endure seeing it billed as a direct contest between Russell and Bottas to impress him.
Fittipaldi made an early start to free practice two, heading out as Romain Grosjean's substitute for Haas, and showed real commitment before both Alfa Romeos and then Carlos Sainz, in his McLaren, began lapping.
The Ferrari-bound Spaniard was soon topping the times before Stroll and then Perez set the pace ahead of Ocon, in his Renault, with a lap in 55.2 " three-tenths inside Russell's pace-setting effort in FP1.
Verstappen then reacted by going top, despite a grumble about his car. "I have the same problem as last week out of Turn One," he said. "It's just hopping."
It enabled Russell, in 54.7, to return to the top while Charles Leclerc remained among the spectators as his Ferrari was under repairs for a 'half-shaft' issue.
With 35 minutes of the 90 remaining, the teams ended their qualifying simulation runs and switched to race set-up preparation. Bottas had another fast lap rubbed out for running off track before he came in, almost sheepishly it seemed.
Russell's pace and potential endorsed Mercedes' view of him as a driver with a big future and left the luckless Bottas facing the possible prospect of failing to beat him in qualifying on Saturday.
In his two years at Williams, the 22-year-old Englishman has never been beaten by a team-mate, even if he has yet to reach a third qualifying top ten shootout. His recent heroics in landing his Williams in Q2 this season earned him the nickname 'Mr Saturday'.
Bottas, a pole-sitter 15 times in his career, knows he faces a difficult challenge if he is to add to that total and stop a new Mr Friday taking the best place on the grid.