Nico Rosberg set the pace in the second practice session at the United States Grand Prix, finishing ahead of Daniel Ricciardo and Mercedes teammate Lewis Hamilton.
Hamilton, trailing Rosberg by 33 points in the championship standings heading into the final stretch of the F1 season, could only finish third as he ended 0.291s slower than the German.
Red Bull's Ricciardo split the pair in Austin, where much of the focus is on the Mercedes duo as they battle it out for the title, but Hamilton could not build on his impressive showing from the first session.
The Englishman started the second practice well, lapping within 0.3s of his teammate and rival on the first runs, but he soon faded and it was Rosberg who led the way, with Ferrari's Sebastian Vettel in fourth ahead of Max Verstappen and Nico Hulkenberg.
Jolyon Palmer, with a big point to prove over the remaining race weekends, posted the 17th-fastest time after a costly spin.
Second practice standings:
1. Nico Rosberg (Mercedes)
2. Daniel Ricciardo (Red Bull)
3. Lewis Hamilton (Mercedes)
4. Sebastian Vettel (Ferrari)
5. Max Verstappen (Red Bull)
6. Nico Hulkenberg (Force India)
7. Sergio Perez (Force India)
8. Jenson Button (McLaren)
9. Fernando Alonso (McLaren)
10. Kimi Raikkonen (Ferrari)
11. Carlos Sainz Jr (Toro Rosso)
12. Kevin Magnussen (Renault)
13. Felipe Nasr (Sauber)
14. Valtteri Bottas (Williams)
15. Daniil Kvyat (Toro Rosso)
16. Felipe Massa (Williams)
17. Jolyon Palmer (Renault)
18. Romain Grosjean (Haas)
19. Esteban Ocon (Manor)
20. Esteban Gutierrez (Haas)
21. Marcus Ericsson (Sauber)
22. Pascal Wehrlein (Manor)
