Lewis Hamilton got his U.S. Grand Prix weekend off to a solid start with the fastest time in first practice, 0.315s faster than teammate and title rival Nico Rosberg.
Hamilton and Rosberg go into this weekend's race split by 33 points, with the British driver in need of a win to inject some hope into his championship campaign. Although the FP1 session counts for nothing in the grand scheme of things, at the last three races the Mercedes driver who has had the edge throughout free practice has gone on to secure pole position on Saturday.
Hamilton held a 1.951s advantage over Max Verstappen in third, but both Red Bull drivers stuck exclusively to the medium tyres -- the slowest compound on offer this weekend -- and are likely to show their true pace later in the day. Hamilton and Rosberg both set their fastest times on soft tyres, although they did use the super-soft tyre for nine lap runs earlier in the session.
Kimi Raikkonen finished the session fourth fastest for Ferrari after using the soft compound throughout the 90 minutes. Nico Hulkenberg was fifth fastest for Force India ahead of Valtteri Bottas in the Williams as the two teams prepare to continue their battle over fourth place in the constructors' championship. Both drivers ran the Halo earlier in the session as part of the FIA's ongoing tests for the cockpit protection device, with Williams opting to run a white version to match its livery.
Daniel Ricciardo was seventh fastest and set his best time on used mediums, while Sebastian Vettel was eighth after his session was interrupted by a loose wing mirror. The mirror came loose when he ran wide exiting the penultimate corner and a piece of bodywork flew up from lower down on the car and took the mirror out.
Both Toro Rossos made into the top ten after using super-soft tyres towards the end of the session to set a quick lap. Kvyat also ran the Halo earlier in the session before having a spin at Turn 18 once it had been removed.
Felipe Massa and Felipe Nasr were 11th and 12th, ahead of Fernando Alonso in the McLaren, who completed 26 laps exclusively on the soft tyres. The two Haas drivers could only manage 15 laps each and both stopped at the end of the pit lane towards the end of the session, finishing down in 14th and 15th.
Marcus Ericsson was 16th ahead of Mexican Alfonso Celis, who drove Sergio Perez's Force India in FP1 as part of his ongoing role as a development driver. Jenson Button was 18th in the second McLaren ahead of Kevin Magnussen's Renault and Jordan King, who was at the wheel of Pascal Wehrlein's Manor for the duration of the session and completed a total of 29 laps.
Jolyon Palmer was 21st in the Renault after sticking exclusively to the mediums and spinning at Turn 18, while Esteban Ocon finished at the bottom of the timesheets in the second Manor.