Nico Rosberg turned the tables on Mercedes team mate Lewis Hamilton with the fastest lap in Brazilian Formula One Grand Prix practice on Friday.
After triple world champion Hamilton had set the pace in the morning with a lap more than half a second faster than the German, Rosberg ended the afternoon 0.458 quicker than the Briton with a lap of one minute 12.385 seconds on soft tyres.
Ferrari's Sebastian Vettel was third fastest in both sessions.
Fernando Alonso brought out red flags early in the afternoon when his McLaren stopped on the track with smoke coming from the engine.
Hamilton, who had delayed his arrival in Brazil due to a fever and after a car accident in Monaco in the early hours of Tuesday morning, has never triumphed in Brazil in eight attempts while Rosberg won last year.
Red Bull's Daniel Ricciardo, using the latest specification Renault engine, was fourth and fifth respectively in the sessions.
With both titles already decided, Hamilton having won his third world crown in Texas last month, teams used the morning session to work on developments for next season with aerodynamic sensors prominent on bodywork.
Mercedes drew a lot of interest for a prominent bulge on the nose that was rumoured to be an ‘S Duct’, a device helping to channel air from under the car to the top surface of the front section.
Ferrari's Kimi Raikkonen, who was fifth and fourth fastest, saw his rear brakes lock into turn four and he tracked across the mud and gravel without further incident.
Lotus reserve Jolyon Palmer, who will be one of the team’s race drivers next year, was involved in the morning’s other moment of near drama when his car was released from the garage into the path of McLaren’s Jenson Button who braked.
Hamilton's return to the track came amid headlines about his party lifestyle with the 30-year-old, whose helmet this weekend carries a tribute to his late boyhood idol Ayrton Senna, recognising he had been overdoing things.
“Heavy partying and not much rest for a week and a half,” the Briton told reporters.
“I am a bit run down. I have been non-stop and trying to fit training in at the same time and not getting a lot of sleep.”
