BOSTON — When they played “O Canada” for the second time, there were no American fans left in the arena to boo.

Instead, the Canadian team stood at the blue line, arm in arm, player and coach, wearing their championship hats while the maple leaf flag was lowered behind the 4 Nations Face-Off trophy and the national anthem reverberated across the Americans’ home ice. The fans who remained, many of them in their red Team Canada jerseys, sang along.

Connor McDavid scored at 8:18 of overtime to give Canada a 3-2 victory over the United States on Thursday night as the North American rivals turned what had been a tune-up for the 2026 Olympics into a geopolitical brawl over anthems and annexation as much as international hockey supremacy.

Or, to put it another way: It was the 51st U.S. state 3, Canada’s 11th province 2.

“You can’t take our country — and you can’t take our game,” Canadian Prime Minister Justin Trudeau posted on X in a cross-border callback to President Donald Trump’s chatter about turning one of the United States’ closest allies into the 51st state.

“A lot of stuff going on with Canada and the USA right now, and us playing against each other was kind of a perfect storm for our sport,” said Nathan MacKinnon, who was selected the MVP of the new tournament with four goals in four games. “It was much more popular than even we would have imagined.”

Jordan Binnington stopped 31 shots — including the last 20 in a row — on the same ice where he helped the Blues win the Stanley Cup as a rookie five years ago. MacKinnon and Sam Bennett also scored for Canada, which made it 2-2 in the second period and then played a scoreless third.

After a flurry of saves by Binnington early in the overtime, Canada gained a faceoff in the U.S. zone and Mitch Marner got the puck along the boards before popping it into the center to McDavid for the winner. The Canadians poured over the boards to celebrate, shook hands with the vanquished Americans, and then took turns skating with the never-before-awarded trophy.

“Just to see the reaction. Just to know what it means to us. I know it’s just a quick tournament, and it’s not an Olympic gold medal or anything like that, but it means the world to our group, as you can see,” McDavid said.

“I hope (the new fans) love it,” he said. “It’s a great game, it’s a great sport and I hope we put on a good show these last couple days and gained some fans, ultimately. You can’t ask for a better show than that.”

The U.S. has lost all but one game against Canada in best-on-best international play dating to the preliminaries of the 2010 Vancouver Olympics; the lone victory was in the 4 Nations round-robin.

“I think guys that are at home watching this, I’m hoping they’re wanting a piece of it,” U.S. forward Dylan Larkin said. “This grew the game really well, but I hope it pushes guys to want a piece of this and then the next generation that got to watch this, they’re going to watch the Olympics next year and hopefully there’s a different outcome.”