World champion Sebastian Vettel walked away unhurt on Friday after slamming his Red Bull car into a wall during opening practice for Sunday's Canadian Grand Prix.
The session was topped by German Nico Rosberg in a Mercedes, clocking a best time of one minute and 15.591 seconds to out-pace nearest rival Fernando Alonso of Ferrari.
Two-time champion Alonso was second quickest ahead of veteran seven-time champion Michael Schumacher of Germany in the second Mercedes, with Brazilian Felipe Massa fourth for Ferrari.
German Vettel crashed after 55 minutes of the 90-minute session, losing control of his car as he lifted over the kerbs at the final chicane before slamming straight ahead into the so-called 'Wall of Champions'.
"I hit the kerb, slid off the track and hit the wall," said a downcast Vettel, 23. "But I'm fine."
Vettel's Red Bull team-mate Mark Webber was down in 12th place, with Vettel's best time of the session good enough only for 16th place.
The two McLarens of Britons Jenson Button, the 2009 champion, and Lewis Hamilton, champion in 2008, finished fifth and sixth respectively, but both men had to overcome problems during a busy session.
Button suffered a complete loss of his Drag Reduction System (DRS) and Hamilton had to pit for repairs to his steering column.
The Circuit Gilles Villeneuve has not been a happy hunting ground for the Red Bull team and they have yet to record a victory in Montreal.
But Vettel is unlikely to be too perturbed as he has overcome similar problems this year at other races, including Turkey, where he missed most of Friday's action but still returned to win the race.
Vettel has a massive 58-point lead on second-place Hamilton in the drivers' title race this year.