Lando Norris was fastest in the first practice for the Formula One Canadian Grand Prix, which was heavily disrupted by wet weather on Friday.
The McLaren driver clocked 1 minute 24.435 seconds to finish ahead of the Ferrari duo of Carlos Sainz and Charles Leclerc. Champion Max Verstappen of Red Bull was only fifth.
The Mercedes cars, meanwhile, were fourth and 10th with Lewis Hamilton and George Russel respectively. Sergio Perez, who this week extended his contract with Red Bull for two more years, was ninth.
The session started on time but the pit exit remained closed for some 20 minutes as motorsport ruling body FIA worked on clearing any standing water on the track after heavy rain and even hail in Montreal.
The session also had to be suspended for a few minutes after Zhou Guanyu lost control of his car and hit the wall at Turn 5.
Second practice is later on Friday, with final practice and qualifying on Saturday ahead of Sunday's showdown.
Champion Max Verstappen tops the standings 31 points ahead of Leclerc.
