Mercedes drivers Valtteri Bottas and Lewis Hamilton set the pace in practice for the Brazilian Grand Prix on Friday, staying in position to secure the Formula One constructors' championship this weekend.
Bottas had a lap of 1min08.846 seconds in the second session at the Interlagos circuit, with world champion Hamilton 0.003 seconds behind.
Ferrari's Sebastian Vettel finished third, 0.073 seconds from Bottas. The Red Bulls of Daniel Ricciardo and Max Verstappen ended in fourth and fifth places, respectively, and Vettel's teammate Kimi Raikkonen was sixth.
Mercedes leads Ferrari in the constructor's championship by 55 points. Hamilton clinched his fifth drivers' title at the Mexican GP two weeks ago.
Verstappen led the first practice session on Friday, with Vettel and Hamilton close behind.
Ricciardo, who was fourth in both sessions, was handed a five-place grid penalty after Red Bull had to replace his turbocharger for the sixth time this season. The Australian driver, who was on pole position in Mexico, also started from the back because of penalties in Italy and Russia.
"It sounds really simple and silly, but bad luck really is the best term I can use," Ricciardo said.
The second session was stopped after nine minutes after Renault's Nico Hulkenberg crashed entering the front stretch. The German driver was not injured but the car was badly damaged.
Rain is expected in qualifying on Saturday and in the race on Sunday.