In what turned out to be a great day for Englishman Russell, he later took pole position for Sunday's Grand Prix, pipping his young championship-leading colleague Kimi Antonelli, while Piastri again had to settle for fourth behind McLaren teammate Lando Norris, just as he had in the sprint.
The real drama of the day in Montreal, though, was that the gloves really looked to be off at Mercedes after 19-year-old Antonelli ended up raging about what he called a "naughty" move from Russell which he felt had shoved him off the track.
The furious teenager, who went off the track twice while battling for the lead with Russell, even demanded his teammate get a penalty, and ended up being scolded by team principal Toto Wolff to "stop the radio moaning".
Ultimately, though, Russell took the victory and the eight points to Antonelli's six, which reduces the third-placed Italian's championship lead to 18 points.
World champ Norris had to settle for the runner's up spot with Piastri not too unhappy with fourth, which keeps him sixth overall in the standings on 48 points, but now 10 behind fourth-placed Norris and 58 behind Antonelli.
The Australian, though, was happy to pull off a daring overtake on the outside to pip Ferrari's Lewis Hamilton on the final chicane, but he later couldn't match Norris's pace again in qualifying while Russell snatched a dramatic pole by 0.064sec from Antonelli at the last gasp.Â
The sprint drama had begun when polesitter Russell was being put under pressure from Antonelli on lap six. On turn one, the teenager swept round the outside, only for the pair to make contact as the Italian was forced across the grass and Russell stayed ahead.
"That was very naughty. Not fair, he pushed me off," Antonelli fumed over the radio, adding: "That should be a penalty, I was alongside the mirror."
Wolff intervened to tell Antonelli to "concentrate on the racing please and not the radio moaning".
Later in the lap, the youngster locked up as he tried to move past on the inside, moving on to the grass, allowing Norris to take second, a position he held despite one last lunge from the Italian.
"If we need to race like this, that's good to know," Antonelli muttered on the radio, with Wolff responding: "Kimi, now is not the time to talk about this. We talk about this internally and not on the radio, OK."
Afterwards, on the press conference sofa next to Antonelli, Russell was unapologetic.
"I was going to close the line because that is my right to do so. A good, hard battle. Came out unscathed," he said.
"Glad we are both sat here now, could have been something different and that is how racing should be."
And after grabbing pole, he revealed: "We've had a good chat since this morning. We're both racing drivers, we both respect one another.
"We'll go racing and we're just battling, the two of us."
Wolff tried to play it all down, telling Sky Sports: "We don't want to start race five with headlines like 'Star Wars' or 'this is escalating', as it's not. It's emotion and he is a young driver."
With agencies
