Mercedes team-mate Nico Rosberg second with McLaren’s Jenson Button third fastest.
Lewis Hamilton set the fastest time of opening practice ahead of the US Grand Prix, ending the 90-minute session almost three tenths of a second clear of team-mate Nico Rosberg.
McLaren’s Jenson Button was the only driver to come close to matching the times set by the Mercedes duo, with the Briton finishing 0.378 adrift of Hamilton’s best time to claim third spot on the timesheet.
Future Red Bull Racing driver Daniil Kvyat impressed with the morning’s fourth fastest time, though his best lap, a 1:40.887, was still 0.9s off Hamilton’s benchmark.
The Toro Rosso driver was followed by Kevin Magnussen in the second McLaren, while Fernando Alonso was sixth for Ferrari.
Sebastian Vettel, who is this weekend set to take a grid penalty related to exceeding the permitted number of elements within his car’s power unit, took seventh place ahead of William’s test driver Felipe Nasr, who had a good outing at the wheel of the FW36. Nico Hulkenberg and 2015 Toro Rosso driver Max Verstappen completed the top 10.
Elsewhere, Red Bull Racing’s Daniel Ricciardo hit trouble with the Australian’s car being hit with an ERS problem that forced him back to pitlane after completing just laps. The problem was such that he didn’t emerge again during the session.
He finished the 90 minutes in 17th place, ahead of Lotus’ Romain Grosjean. The Frenchman ran a 2015 test nose for Lotus in the early part of the session before reverting to the team’s usual 2014 twin tusk nose late on.
With Caterham and Marussia absent from the event, just 18 cars took part in the session, which also saw a number of drivers undertake a ‘virtual safety car’ test being analysed as one possible response to the accident suffered by Marussia driver Jules Bianchi in Japan.
2014 United States Grand Prix – Free Practice 1 Result1 Lewis Hamilton Mercedes 1:39.941 282 Nico Rosberg Mercedes 1:40.233 0.292 323 Jenson Button McLaren 1:40.319 0.378 274 Daniil Kvyat Toro Rosso 1:40.887 0.946 335 Kevin Magnussen McLaren 1:40.987 1.046 296 Fernando Alonso Ferrari 1:41.065 1.124 277 Sebastian Vettel Red Bull Racing 1:41.463 1.522 208 Felipe Nasr Williams 1:41.545 1.604 199 Nico Hulkenberg Force India 1:41.722 1.781 2410 Max Verstappen Toro Rosso 1:41.785 1.84411 Felipe Massa Williams 1:41.907 1.96612 Kimi Räikkönen Ferrari 1:41.965 2.02413 Pastor Maldonado Lotus 1:42.329 2.38814 Adrian Sutil Sauber 1:42.333 2.39215 Sergio Perez Force India 1:42.359 2.41816 Esteban Gutierrez Sauber 1:42.516 2.57517 Daniel Ricciardo Red Bull Racing 1:42.598 2.65718 Romain Grosjean Lotus 1:43.229 3.288