World champion Lewis Hamilton was denied a practice hat-trick by Mercedes team-mate Valtteri Bottas ahead of tomorrow's Brazilian Grand Prix.
Hamilton, who was fastest in both sessions at Interalgos yesterday, was beaten to top spot by just three thousandths of a second in final practice.
The 32-year-old trailed Bottas's best effort of one minute and 09.281 seconds with Ferrari's Kimi Raikkonen just 0.045 sec adrift of his Finnish countryman. Sebastian Vettel was fourth.
Hamilton has vowed not to take his foot off the accelerator as he bids to end his championship-winning season on a high, but he has faced a stern test from Bottas here so far this weekend.
The Finn kept Hamilton honest for much of Friday, and he was marginally faster than his team-mate in the last session before qualifying here at Interlagos later.
Bottas is 15 points adrift of Vettel in the battle for second place in this year's championship and will be heartened to have finished ahead of the Ferrari driver in all three practice sessions.
Darks clouds lingered over the 2.7-mile track for the one-hour session, but while the threat of rain never materialised, it could yet play a part in qualifying later.
Red Bull's Daniel Ricciardo finished fifth in the order ahead of McLaren's Fernando Alonso.
Max Verstappen, a winner last time out, finished ninth following a trip across the grass after he lost control of his Red Bull at Turn 13.