Mercedes driver Lewis Hamilton has recorded the fastest time in the first practice session at the United States Grand Prix in Austin, Texas.
The Brit, who currently has a 17-point lead over championship rival and teammate Nico Rosberg with three races to go, finished above the German in today's practice.
Jenson Button led the way in his McLaren in the early stages of the session, but eventually ended third on the timesheet in Texas.
Sebastian Vettel, who will take part in qualifying despite reports that he would miss out because of an engine penalty, clocked the seventh-fastest time of the session.
With less than 20 minutes remaining in the session, Daniel Ricciardo could only manage five laps around the circuit due to an engine issue with his Red Bull.
In contrast, Daniil Kvyat, Max Verstappen and Kevin Magnussen led the way in terms of laps by clocking up 22 during the session.
Full practice standings:
1. Lewis Hamilton (Mercedes)
2. Nico Rosberg (Mercedes)
3. Jenson Button (McLaren)
4. Daniil Kvyat (Toro Rosso)
5. Kevin Magnussen (McLaren)
6. Fernando Alonso (Ferrari)
7. Sebastian Vettel (Red Bull)
8. Felipe Nasr (Williams)
9. Nico Hulkenberg (Force India)
10. Jean-Eric Vergne (Toro Rosso)
11. Felipe Massa (Williams)
12. Kimi Raikkonen (Ferrari)
13. Pastor Maldonado (Lotus)
14. Adrian Sutil (Sauber)
15. Sergio Perez (Force India)
16. Esteban Gutierrez (Sauber)
17. Daniel Ricciardo (Red Bull)
18. Romain Grosjean (Lotus)
