Lewis Hamilton signalled his intentions to reclaim the Formula One drivers' championship lead from Mercedes team-mate Nico Rosberg, after setting the pace in practice for the Canadian Grand Prix.
The Briton, a three-time winner on the Circuit Gilles Villeneuve, lapped the island track in one minute 16.118 seconds on an overcast afternoon on the banks of the St. Lawrence River.
Ferrari's former world champion Fernando Alonso upstaged the mighty Mercedes team by toping the timesheets in the morning session but Hamilton and Rosberg quickly restored order going one-two later in the day.
Hamilton and Rosberg arrived in Canada downplaying a spat between the two that had dominated talk up and down the paddock but on the track their rivalry remained firmly in place.
The German, who snapped Hamilton's four-race win streak in Monaco to replace his team mate atop the standings, was 0.175 seconds behind the Briton, setting the stage for another hotly-contested battle for pole on Saturday.
Mercedes have started every race from pole claiming five successive one-two finishes.
Rosberg leads overall with 122 points to Hamilton's 118 while Mercedes have a hefty 240 points in the constructors' standings, with Red Bull second on 99.
Red Bull continued to show improvement as quadruple world champion Sebastian Vettel, a winner in Montreal last year, posted the day's third best time.
Ferrari, who had also been struggling to match the pace of Mercedes, saw Kimi Raikkonen clock the fourth best effort followed by Alonso, the 2006 Canada champion and runnerup last year.
The Williams of Filipe Massa and Valtteri Bottas were sixth and seventh.