Lewis Hamilton has finished fastest in the first practice session ahead of this weekend's Korean Grand Prix.
The McLaren driver was impressive throughout the morning session and showed signs of progression to extend his lead on the final lap.
Fernando Alonso came in second behind Hamilton despite some problems with his Ferrari in the latter stages of his performance in Yeongam.
Felipe Massa continued his good recent form to join teammate Alonso in the top three.
Jenson Button looked off the pace as he finished 10th, while defending champion Sebastian Vettel came in fifth.
The second practice session will begin at around 6am.
1. Hamilton
2. Alonso
3. Webber
4. Massa
5. Vettel
6. Schumacher
7. Rosberg
8. Grosjean
9. Di Resta
10. Button
11. Raikkonen
12. Maldonado
