AUSTIN, United States (AFP) - Championship leader Lewis Hamilton topped the times again in Saturday morning's third and final free practice session for Sunday's United States Grand Prix.
The 29-year-old Briton, who was fastest in both practice sessions on Friday, was more than seven-tenths of a second clear of his Mercedes team-mate and title rival Nico Rosberg.
It was another dominant performance from Hamilton who holds a 17 points lead ahead of Rosberg with three races, including the season finale Abu Dhabi Grand Prix where double points will be awarded, remaining.
Felipe Massa was third quickest for Williams ahead of his team-mate Valtteri Bottas as the English team proved again they are the most improved outfit this season.
The Williams pair's big effort lifted them clear of fifth placed two-time champion Fernando Alonso of Ferrari and sixth placed Daniel Ricciardo of Red Bull.
Nico Hulkenberg was seventh for Force India ahead of compatriot Adrian Sutil of Sauber, Kimi Raikkonen in the second Ferrari and Jenson Button who was 10th for McLaren.