Russell, starting on pole, had traded the lead with Antonelli in a thrilling battle before coming to a halt by the side of the track on the 30th of 68 laps at Montreal's Circuit Gilles Villeneuve.
"Not the way I wanted to win. It was meant to be a good fight with George, but we will take it," said Antonelli.
Ferrari's Lewis Hamilton took second place, 10.7 seconds behind the 19-year-old Italian, with Red Bull's Max Verstappen a close third and taking his first podium of the season.
Antonelli increased his lead over Russell from 18 to 43 points after five grands prix, all won by Mercedes, and three Saturday sprints.
He is the first Italian since Alberto Ascari in 1952 to win four in a row, and also the first driver in the history of F1 to take his first four wins consecutively. His podium was the 300th by a Mercedes driver since they returned to Formula One as a works team in 2010.
Russell, who has suffered bad luck already this season but had won the Saturday sprint, was lost for words after his hopes vanished at a stroke.
"Just everything turned off all of a sudden," he said. "Just went into the corner, engine stopped, no electronics, no proper braking. I'm pretty damned frustrated with what's happened, but what more can I do?"
Ferrari's Charles Leclerc finished an unhappy fourth, despite a half-spin, as the last unlapped driver with Isack Hadjar fifth for Red Bull - after two penalties - and Franco Colapinto continuing to score big points with sixth for Alpine.
Liam Lawson was seventh for Racing Bulls, ahead of Alpine's Pierre Gasly, Williams' Carlos Sainz, and Haas's Oliver Bearman.
Neither McLaren driver scored, with Oscar Piastri 11th and penalised 10 seconds for a lap 15 collision that put Williams' Alex Albon out of the race, while reigning world champion Lando Norris retired on lap 38 with a gearbox problem.
Mercedes now lead Ferrari by 72 points in the constructors' standings.
A 'Rain Hazard' had been declared on Saturday, but the conditions, although cold and slippery, were not as bad as feared.
Both McLarens gambled by starting on the intermediate tyres, a mistake that Piastri recognised even as the field circulated before the getaway and that led to them pitting early.
After two extra formation laps, the first attempt aborted when rookie Arvid Lindblad was unable to get his Racing Bulls into gear and alerted race control. The race started with Norris storming into the lead from third place.
Antonelli made a better getaway than Russell and slotted into second, taking the lead when Norris pitted on lap three for mediums.
Russell passed Antonelli down the straight on lap six, with the Italian locking up behind him and running wide to avoid contact, and the two Mercedes drivers then traded the lead several times on lap 13.
Antonelli was back in front on lap 22, and lapped Norris at the start of the next one, but Russell took the lead again before they went wheel to wheel with the Italian overshooting the hairpin but getting ahead on lap 24.
The teenager was told to give the place back, which he did reluctantly. "Why, mate? He pushed me off. And I was ahead. Like, what's the point?" he asked.