Lewis Hamilton has gone quickest in first practice ahead of Sunday's Korean Grand Prix in Yeongam.
The Mercedes man came in ahead of Red Bull duo Sebastian Vettel and Mark Webber, who finished second and third respectively.
His teammate Nico Rosberg clocked the fourth-fastest time at the Korea International Circuit.
The session ended in dramatic fashion as Kimi Raikkonen crashed out, leaving his Lotus Renault machine noticeably damaged.
The Finn, who ended up finishing seventh fastest, walked away unscathed.
Top 10: 1.
2. Sebastian Vettel
3. Mark Webber
4. Nico Rosberg
5. Jenson Button
6. Fernando Alonso
7. Romain Grosjean
8. Kimi Raikkonen
9. Sergio Perez
10. Felipe Massa