Lewis Hamilton set the pace in second practice at the Brazilian Grand Prix as Mercedes dominated the first day at the penultimate race of the season.
Hamilton and team-mate Valtteri Bottas were first and second in both sessions, the new champion just 0.048 seconds ahead of the Finn in the afternoon.
Red Bull’s Daniel Ricciardo was next, 0.228secs off Hamilton and 0.132secs ahead of Ferrari’s Sebastian Vettel.
Red Bull’s Max Verstappen was fifth ahead of Ferrari’s Kimi Raikkonen.
Hamilton clinched the championship at the last race in Mexico but says he is determined to win the final two races to keep the pressure on Ferrari going into the winter, following their collapse in the championship.
That is a contrast with his approach the last time he won the title early, in 2015, when his team-mate Nico Rosberg won the final three races of the season and used it as a launch pad for a strong start to the following year, which he ended as champion.
Hamilton has stamped his authority on the weekend so far, fastest in both sessions and also marginally quickest on the race-simulation runs later in the afternoon when the team practice for the race.
Vettel was closest to Hamilton on race pace, within 0.1secs a lap of the Mercedes on average on the super-soft tyres, with Bottas a similar difference behind and Ricciardo next.
But Hamilton was blisteringly fast when he switched to the ‘soft’ tyre – more than 0.5secs a lap on average quicker than Bottas, who was comfortably quicker than Ricciardo as the three were all out on track at the same time.
“We planned to run long to see what the tyres were like,” said Vettel. “Car-wise we can fine-tune the balance and that should help us get the pace up for qualifying and race but it will be difficult to match Mercedes.”
The demanding Interlagos track provoked a couple of spins, Haas driver Romain Grosjean and Sauber’s Marcus Ericsson both losing control without suffering damage.
Ricciardo and both Toro Rosso drivers have been hit with engine-related grid penalties – 10 places for the Australian and Brendon Hartley, who was 17th fastest on Friday afternoon, and a total of 25 for Frenchman Pierre Gasly, who was a place ahead of the New Zealander.
Outside the top six drivers, Force India’s Esteban Ocon was seventh quickest, ahead of the Williams of Felipe Massa, who announced his retirement at the end of the season before the race, Renault’s Nico Hulkenberg and Fernando Alonso’s McLaren.
Alonso suffered engine problems that cut his running and resurfaced during his race-simulation run. His team-mate Stoffel Vandoorne, who had a spin when out to do his qualifying simulation run on the super-soft tyres, was three places and just over 0.2secs adrift.