Lewis Hamilton has recorded the fastest time in the first practice session ahead of Sunday's Singapore's Grand Prix.
The Mercedes driver edged ahead of Red Bull duo Mark Webber and Sebastian Vettel, while teammate Nico Rosberg ended the session in fourth position.
Lotus Renault's Kimi Raikkonen was in fifth, while the Finn's future teammate, Fernando Alonso, was in seventh place.
Jenson Button, who has just signed a new deal with McLaren, was 14th, with Paul di Resta in 15th position for Force India.
Full standings:
1. Lewis Hamilton (Mercedes)
2. Mark Webber (Red Bull)
3. Sebastian Vettel (Red Bull)
4. Nico Rosberg (Mercedes)
5. Kimi Raikkonen (Lotus Renault)
6. Romain Grosjean (Lotus Renault)
7. Fernando Alonso (Ferrari)
8. Sergio Perez (McLaren)
9. Jean-Eric Vergne (Toro Rosso)
10. Esteban Gutierrez (Sauber)
11. Pastor Maldonado (Williams
12. Felipe Massa (Ferrari)
13. Valtteri Bottas (Williams)
14. Jenson Button (McLaren)
15. Paul di Resta (Force India)
16. Adrian Sutil (Force India)
17. Nico Hulkenberg (Sauber)
18. Daniel Ricciardo (Toro Rosso)
19. Jules Bianchi (Marussia)
20. Max Chilton (Marussia)
21. Giedo van der Garde (Caterham)
22. Charles Pic (Caterham)