Nico Rosberg came out on top in the first practice session of the Russian Grand Prix as he looks to claim his seventh win on the bounce.
The Mercedes driver, who has a 36-point lead over teammate and reigning Formula 1 champion Lewis Hamilton, clocked the fastest time of 1:38.127.
Hamilton was second-fastest in the standings, while Ferrari's Sebastian Vettel and Kimi Raikkonen recorded the third and fourth quickest times respectively.
Felipe Massa was just outside the top four in his Williams, while Daniel Ricciardo went round the track sixth-quickest in the field.
Jenson Button suffered a spin in his McLaren on turn 15 after drifting out too wide, and a few minutes later, Vettel had the same problem.
Aside from that, it was a relatively incident-free session in Russia.
First practice standings:
1. Nico Rosberg (Mercedes)
2. Lewis Hamilton (Mercedes)
3. Sebastian Vettel (Ferrari)
4. Kimi Raikkonen (Ferrari)
5. Felipe Massa (Williams)
6. Daniel Ricciardo (Red Bull)
7. Valtteri Bottas (Williams)
8. Daniil Kvyat (Red Bull)
9. Sergio Perez (Force India)
10. Carlos Sainz Jr (Toro Rosso)
11. Jenson Button (McLaren)
12. Fernando Alonso (McLaren)
13. Sergey Sirotkin (Renault)
14. Felipe Nasr (Sauber)
15. Max Verstappen (Toro Rosso)
16. Esteban Gutierrez (Haas)
17. Romain Grosjean (Haas)
18. Jolyon Palmer (Renault)
19. Marcus Ericsson (Sauber)
20. Pascal Wehrlein (Manor)
21. Rio Haryanto (Manor)
22. Alfonso Celis (Force India)