Mercedes’ Lewis Hamilton set the pace during the opening practice session for the United States Grand Prix.
Hamilton, who can clinch the title this weekend, worked his way down to a 1:36.335 on the Super Soft tyres, after a session which began in damp conditions, following earlier rain.
Ferrari’s Sebastian Vettel finished as Hamilton’s nearest opponent, albeit half a second behind the Briton, with Mercedes’ Valtteri Bottas third.
Red Bull’s Max Verstappen, who had led the way on Intermediate tyres, wound up fourth best, while McLaren’s Stoffel Vandoorne took fifth, as the lead driver on the Ultra Softs.
Williams’ Felipe Massa was sixth, in front of Ferrari’s Kimi Räikkönen and Force India pair Esteban Ocon and Sergio Pérez, the latter duo clocking their best times on Softs.
Carlos Sainz Jr. made his first appearance behind the wheel of the Renault R.S.17 and rounded out the top 10, three places in front of team-mate Nico Hülkenberg.
They were split by Haas’ Kevin Magnussen, who was involved in an unusual post-session blocking spat with Vettel, and Williams rookie Lance Stroll.
Brendon Hartley began his debut Formula 1 weekend in a measured 14th place, ahead of Romain Grosjean and Daniel Ricciardo, while Sean Gelael went off twice en route to 17th spot.
Sauber pair Marcus Ericsson and Charles Leclerc took 18th and 19th respectively, as Fernando Alonso finished at the foot of the table, without a timed lap, due to a hydraulics issue.
Vandoorne (five places), Hulkenberg (20 places) and Hartley (25 places) have already picked up grid penalties for engine changes.
