Formula One world champion Lewis Hamilton clocked the best time in a dusty first practice session for the Canada Grand Prix on Friday as Mercedes broke in an upgraded engine.
It was business as usual for Mercedes as Britain's Hamilton lapped the island circuit named after Ferrari great Gilles Villeneuve with a fastest time of one minute 12.767 seconds, 0.147 ahead of Finnish team mate Valtteri Bottas.
Mercedes have dominated on every circuit this season, with Hamilton and Bottas winning all six races, crossing one-two in five of them.
Five times world champion Hamilton sits 17 points clear of Bottas at the top of the standings and served notice that he will again be a threat as he bids to equal Michael Schumacher's seven Canadian Grand Prix victories between 1994 and 2004.
Charles Leclerc was third quickest for Ferrari, who have yet to get in gear this season but are hoping to provide a bigger threat to Mercedes on a power circuit that plays to their strengths.
Leclerc's team mate Sebastian Vettel, who won from pole here last year, could only manage the fifth best time behind Red Bull's Max Verstappen.
Several cars spun in the opening session on what Verstappen complained was an "insanely dirty" track.
Antonio Giovinazzi was involved in the most serious slip up when he spun his Alfa Romeo into the wall midway through the session, briefly bringing out the virtual safety car.