Nico Rosberg and Lewis Hamilton have come fastest in first practice for the first Austrian Grand Prix since 2003.
Championship leader Rosberg clocked the quickest time as the drivers got their first look at the Red Bull Ring track, but the home team had a disappointing session.
Both Sebastian Vettel and Daniel Ricciardo finished outside of the top 10, as did the two Lotus cars, but Williams and McLaren put in promising performances ahead of Saturday's qualifying.
In rainy conditions which restricted lap opportunities, Rosberg went 0.1 seconds quicker than Mercedes teammate and title rival Hamilton, with Ferrari's Fernando Alonso the same time adrift.
Alonso's colleague Kimi Raikkonen, who finished on the podium the last time that Austria hosted a grand prix, could only go 11th quickest, with both Force India's inside the top seven.
Felipe Massa in the Williams and Jenson Button in the McLaren split them and the top three, and their teammates Valtteri Bottas and Kevin Magnussen also did well in the morning.
Lotus drivers Pastor Maldonado and Romain Grosjean struggled along with the Red Bulls, whose defending champion Vettel survived a nasty spin, but could not go better than 15th quickest.
First practice results:
1. Nico Rosberg (Mercedes)
2. Lewis Hamilton (Mercedes)
3. Fernando Alonso (Ferrari)
4. Felipe Massa (Williams)
5. Jenson Button (McLaren)
6. Sergio Perez (Force India)
7. Nico Hulkenberg (Force India)
8. Valtteri Bottas (Williams)
9. Kevin Magnussen (McLaren)
10. Jean-Eric Vergne (Toro Rosso)
11. Kimi Raikkonen (Ferrari)
12. Daniil Kvyat (Toro Rosso)
13. Daniel Ricciardo (Red Bull)
14. Esteban Gutierrez (Sauber)
15. Sebastian Vettel (Red Bull)
16. Romain Grosjean (Lotus)
17. Pastor Maldonado (Lotus)
18. Jules Bianchi (Marussia)
19. Max Chilton (Marussia)
20. Kamui Kobayashi (Caterham)
21. Adrian Sutil (Sauber)
22. Marcus Ericsson (Caterham)