Russell had started on pole in Montreal and was locked in a titanic duel with Antonelli across the first half of the race, trading positions and even making contact as the pair fought for the lead.
But his challenge came to a sudden halt on lap 30 when a power unit failure left him stranded, allowing Antonelli to inherit the lead and ultimately win the race.
The result extends Antonelli’s advantage at the top of the standings to 43 points after just five rounds, with Russell now forced into what he described as a damage-limitation mindset for the remainder of the season.
“I mean, right now it’s his to lose,” Russell said after the race when asked about the title fight.
“It’s so many points ahead. It feels like… the gods don’t want me to be in this fight – when I look at the safety car timing in Japan, breaking down in China Q3 [while] fighting for pole, breaking down from the lead here today.
“But pressure’s off. Go out, enjoy every single race, try and win every single race – and I’ve got nothing to lose, so I don’t want to be stood here talking like that.
“It is, of course, frustrating and I want to be in that fight. Hopefully, the luck turns.”
Russell’s frustration was compounded by the nature of his retirement, with the Mercedes driver explaining the car shut down without warning as he ran at the front.
“Everything turned off all of a sudden as I went into the corner,” he said.
“The engine stopped, no electronics, no proper braking.”
Despite the setback, Russell said there was satisfaction in the performance itself, particularly given the intensity of his on-track battle with Antonelli throughout the weekend.
“I’m proud of my weekend, pole the sprint, won the sprint, pole in qualifying,” he said.
“I was leading when I stopped. I had a good battle with Kimi.
“Hard battles, I really loved the battle and I wanted to continue for 30 more laps. I would have loved to see how it would have panned out but here we are.”
Antonelli’s win marked his fourth consecutive Grand Prix victory, further underlining his rapid rise in just his second season in F1.
Mercedes team principal Toto Wolff described the internal battle between the pair as both a privilege and a risk, adding the result was bittersweet.
“You’re extremely happy for one driver and his driving, and then you feel gutted for the other ones. So it’s difficult,” Wolff told Sky Sports.
“But in any case, Kimi has done a splendid today, and deserved to win.
“But George, shame, he was in the lead of the race. We half enjoyed watching them, how they fought it out. Wish we would have had a one and a two.
“As long as we maintained that gap, it was okay watching it. But it obviously can go wrong.
“Not even because one wants to hit the other one, but simply we Kimi locking up the wheels and you can take two cars out.”
Wolff confirmed Mercedes never intervened to limit the fight between the pair, praising the freedom both drivers had under identical strategies.
“You see how close that is. They were giving each other room, which is great,” he said.
“We never changed the engine strategies. So the one defending had tools he needed. The one attacking had the tools he needed. It made no difference between the two.
“But obviously it was a luxury problem. I would hope we go like this for much longer in the season.
“But you can’t discount the others. And if it was closer behind us, if we were a threat to lose the position, we would definitely jump in and say, let’s not lose so much time with each other.”
Despite Russell suggesting he is effectively out of the championship fight, Wolff insisted he remains firmly in the title picture with 17 races still to run.
“I mean, yeah, it’s a 40-point, or 43-point gap. But there is, how many, 17 more races to go?” he said.
“There’s so many points to score that this is going to go all the way to the end.”
Despite Russell’s retirement, Mercedes still maintain their lead at the top of the constructors’ championship, leading Ferrari by 72 points.
