Ferrari's Fernando Alonso has clocked the fastest time in the first practice session ahead of the Canadian Grand Prix in Montreal.
Mercedes's Lewis Hamilton, who missed out on winning his fifth consecutive race in Monaco last month after his teammate Nico Rosberg rode to victory, finished the session second quickest.
Rosberg recorded the third-fastest time, while Red Bull's Sebastian Vettel ended the session fourth quickest on the track.
Kevin Magnussen set the pace early on in the session by clocking 1:19.820s in his McLaren, with Lotus driver Romain Grosjean following one second behind.
Hamilton started off strongly on the track, while Felipe Massa was forced to retire after his Williams developed pump failure during the opening session.
Jules Bianchi's Marussia car sustained track rod damage after it connected with the wall, but the driver is expected to be back on the course for the second practice of the day.
First practice standings:
1. Fernando Alonso (Ferrari)
2. Lewis Hamilton (Mercedes)
3. Nico Rosberg (Mercedes)
4. Sebastian Vettel (Red Bull)
5. Valterri Bottas (Williams)
6. Daniel Ricciardo (Red Bull)
7. Jenson Button (McLaren)
8. Kevin Magnussen (McLaren)
9. Jean-Eric Vergne (Toro Rosso)
10. Nico Hulkenberg (Force India)
11. Sergio Perez (Force India
12. Adrian Sutil (Sauber)
13. Romain Grosjean (Lotus)
14. Daniil Kvyat (Toro Rosso)
15. Pastor Maldonado (Lotus)
16. Felipe Massa (Williams)
17. Estaban Gutierrez (Sauber)
18. Jules Bianchi (Marussia)
19. Max Chilton (Marussia)
20. Marcus Ericsson (Caterham)
21. Alexander Rossi (Caterham)