Mercedes driver George Russell has enjoyed a stellar day in Canada with victory in the sprint race and qualifying on pole for the grand prix, but suffered the season's first flashpoint with teammate and championship rival Kimi Antonelli.
The Mercedes duo nearly took each other out battling for the lead on lap six of the 23-lap sprint at the Circuit Gilles Villeneuve on Sunday morning, AEST.
The pair did make contact, and the battle continued for a few more corners before a lock-up from Antonelli gave Russell a chance to establish a lead and go on to win.
Antonelli would finish third after being overtaken by McLaren's Lando Norris, while Oscar Piastri made a late overtake on Ferrari's Lewis Hamilton to claim fourth.
The wheel-to-wheel battle, which resulted in Antonelli going off the track and cutting the first corner, drew the ire of the 19-year-old championship leader.
But Russell, who reduced his deficit in the championship to 18 points with the sprint race win, believed his defensive driving to maintain the lead was fair racing.
"From my side, I didn't think I did anything wrong and it wasn't investigated. I guess race directors and stewards thought the same."
Russell then backed up his win with a blistering final lap in grand prix qualifying to secure pole position for the race on Monday morning, AEST.
Antonelli looked most likely to claim pole when his final flying lap pipped the McLaren duo of Norris and Piastri, but Russell's 1 minute 12.578 seconds was good enough for the top spot by just 0.068 seconds.
"It is always challenging to come back from the sprint as the car feels very different," Russell said.
"That last lap came from nowhere, such a great feeling when it was such a challenging session."
Piastri fourth in sprint race and grand prix qualifying
Oscar Piastri has qualified fourth fastest for the Canadian Grand Prix, after also placing fourth in the sprint race at Montreal.
The McLarens continue to show they are capable of putting up a fight with the Mercedes, with Norris battling Russell and Antonelli for the win.
Starting fourth, Piastri was overtaken by Ferrari's Lewis Hamilton at the start, taking away any chance of joining his teammate in the battle for the podium spots.
The Australian would make a late lunge on the seven-time world champion late in the race to reclaim fourth position, with a stunning move at the final chicane.
"I think the pace was pretty good, I was just stuck most of the race," Piastri said after the sprint.
"I think the pace was encouraging and if we have a better qualifying, then we can be in the mix.
Piastri again showed he can be in the fight on Monday morning with his fourth place in qualifying.
The Victorian's time of a 1:12.781 was 0.203 seconds off Russell's pole lap, and just 0.052 seconds off his McLaren teammate Norris, who is third.
"We got closer, but not quite enough," Piastri said, as reported by F1.com.
ABC Sport will have a live blog of the Formula 1 Canadian Grand Prix from 4:30am AEST on Monday, May 25.