BOSTON -- When "O Canada" played for the second time Thursday night, there were no American fans left in the arena to boo.
Instead, the Canadian players and coaches stood at the blue line, arm in arm, wearing their championship hats while the maple leaf flag was lowered behind the 4 Nations Face-Off trophy and their 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 tuneup for the 2026 Olympics into a geopolitical brawl over anthems and annexation as much as international hockey supremacy.
"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 added. "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."
It was the second time an NHL international tournament was decided by an OT goal; Darryl Sittler won it for Canada at the 1976 Canada Cup.
Nathan MacKinnon and Sam Bennett also scored for Canada on Thursday night. Jordan Binnington stopped 31 shots -- including the last 20 in a row -- on the same ice where he helped the St. Louis Blues win the Stanley Cup as a rookie five years ago.
MacKinnon, who opened the scoring with his fourth 4 Nations goal, was named tournament MVP. He is the third Canadian player to average at least a goal per game in an NHL international tournament, joining Hall of Famers Mario Lemieux at the 1987 Canada Cup and Mike Bossy at the 1981 Canada Cup.
"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," MacKinnon said. "It was much more popular than even we would have imagined. It was getting so much attention from our whole continent."
Brady Tkachuk and Jake Sanderson scored for the U.S., and Connor Hellebuyck stopped 22 shots in regulation and three more in OT. The U.S. has lost all but one game against Canada in best-on-best international play dating to the preliminary round of the 2010 Vancouver Olympics; the lone victory was in the 4 Nations round-robin Saturday, a game so good it turned Thursday's sequel into one of the most anticipated international hockey events in decades.
"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."
The already-ripe rivalry took on added intensity with the cross-border animosity after U.S. President Donald Trump's tariff threats and talk of making Canada the 51st state. Trump called the American team Thursday morning to wish it well, then turned to social media with another jab at Canadian Prime Minister Justin Trudeau about annexation.
"You can't take our country -- and you can't take our game," Trudeau posted on social media after Canada's victory.
The political backdrop coupled with the quality of the round-robin game, which the United States won 3-1 on Saturday, brought the atmosphere of a Stanley Cup Final or Olympic gold medal game to TD Garden.
Fans in their team jerseys waved flags, shouted for their countrymen and continued the booing of the opposing national anthem that has become a nightly undercard for a tournament that was the return of NHL stars to the international scene after missing the past two Winter Olympics.
The American fans chanted "U-S-A! U-S-A!" to spur the home team. In the third period, a cheer of "Johnny Hockey! Johnny Hockey!" reminded the players that they were playing for the memory of former Boston College and Calgary Flames star Johnny Gaudreau, who, along with his brother, Matthew, was killed by an alleged drunk driver while bicycling in New Jersey on the eve of their sister's wedding last summer.
"Miracle on Ice" Olympic hero and honorary U.S. captain Mike Eruzione wore a Gaudreau jersey during a pregame ceremonial puck drop with Canadian counterpart Wayne Gretzky.
It was 2-2 after 40 minutes and it stayed that way in the third period and the first eight minutes of overtime. After a flurry of saves by Binnington, the Canadians gained a faceoff in the U.S. zone and Mitch Marner got the puck along the boards before popping it into the center for McDavid.
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.
"We wanted this one," Canada forward Mark Stone said. "You've got 40 million Canadians, sitting at home, and you feel the energy. Anytime you have the chance to play for our country, or the flag on our chest, it's a special, special feeling. ... It brings us together. And just glad we got to get this one."
The Associated Press contributed to this report.