The goal came just seven seconds after the Americans had scored two quick goals to overcome a 4-2 deficit to produce what looked like an overtime finale. Ty Dellandrea added an empty netter for the victors.
Canada had spotted its arch-rivals two early goals, then scored three in the second period and another early in the third to go up 4-2, but the Americans showed no quit.
Three of Canada's goals came with the man advantage and two from captain Barrett Hayton, who also had an assist. Lafreniere, meanwhile, added three assists. Shane Pinto had two power-play goals and an assist for the U.S.
Although great rivals, the teams had played on Boxing Day only five times previous in 42 World Juniors, Canada winning four of them and going on to win gold three times (1990, 1993, 1996). The only U.S. win, however, was the most recent December 26 tilt, in 2016, when the Americans won a bronze medal. As for the four losses? The Americans never finished higher than fourth.
"It was a dream come true just to play in the game, and to come out with the win made it even better," enthused Connor McMichael. "We're looking forward to playing Russia [on Saturday]."
"We didn't get too high or too low," noted defenceman Jacob Bernard-Docker. "We didn't get too down when we were trailing 2-0, and then when we got up we kept an even keel."
"It was a tough way to lose," admitted American forward Arthur Kaliyev, but hopefully we can learn from this and come out stronger tomorrow against Germany. Both teams are skilled and can score a lot of goals, but we have to be better on the defensive side."
Augmented by an early power play, the Americans had the much stronger start. Pinto tipped in a Zac Jones point shot at 3:10 to get the U.S. on the board, and they had the better speed and puck control for several minutes.
Although the Canadians had a large contingent of fans, they were pretty quiet until Lafreniere threw a solid checkmidway through the period, followed by three others on the shift by his teammates, to ignite the team and the crowd.
But the Americans weathered the storm, supporting goalie Spencer Knight to perfection. Canada had a great deal of the play in the middle of the period, but not many scoring chances and no goals to show for it.
The Canadians also had a power play of their own which they couldn’t convert, and then the U.S. had a man advantage late and doubled their lead with another fortuitous goal. This time it was a great pass from Trevor Zegras to Kaliyev in the slot. He used his phenomenal one-timer to beat Nicolas Daws a second time at 18:32.
Canada dominated the second period, though, and was full measure for a complete turnaround in its fate. The Canadians got on the board at 3:31 thanks to a nice pass by Akil Thomas to McMichael, skating to the net. He merely redirected Thomas’s pass and beat Knight with the shot.
Three minutes later, Canada tied the game just seven seconds into a power play. Hayton one-timed a shot from the right boards to make the game all square. Six and a half minutes later, on another power play, Nolan Foote ripped another shot from a similar angle to give Canada a 3-2 lead.
It was a lead Canada held into the dressing room, but only by a fraction of a second. On a late power play of its own, the Americans scored, but video replay showed the puck crossed the goal line just after the period had ended.
"We didn't have a lot of momentum in the first, but we pushed hard and fought back and turned things around in the second," McMichael added.
Canada doubled its lead midway through the final period on another power play. Althoguh Hayton snapped home his second with the extra man, it was the sensational pass from Lafreniere that made the play.
Two minutes later, though, Nick Robertson wired a shot using Bernard-Docker as a screen to make it a close game again. The U.S. got a power play soon after, but Canada's penalty killers were perfect in their own end and maintained their lead, but another penalty soon after did them in.
Robertson made a great cross-crease pass to Pinto, who redirected the puck past Daws's skate to tie the score. That set the stage for Lafreniere's heroics.