Team captain Ashton Bell scored the overtime winner for Canada in a 1-0 victory over the United States at the women's world under-18 hockey championship Tuesday.
Canada capped the preliminary round 3-0, while the Americans finished 2-0-1. Both teams will play in Friday's semifinals.
Bell, from Deloraine, Man., scored at 1:57 of overtime with a top-corner wrist shot.
Goaltender Danika Ranger of Uxbridge, Ont., earned a 23-save shutout, while Alex Gulstene turned away 29 of 30 shots in the American net.
Canada and the U.S. have met in the final of all nine women's world under-18 tournaments to date with the Americans holding a 5-4 edge in gold medals won.
"We all had that drive to play against the U.S. team because it's such a great rivalry and I think we battled hard throughout the whole game and it was just a great game overall," Ranger said.
Both countries were scoreless on four power-play opportunities.
"I think (this win) gives us a little bit of momentum, but I think the way we won is the most important thing," Canadian coach Troy Ryan said.
"We played together as a team and we did a lot of little things well. This win gives us a little bit of confidence and more importantly it also gives us a bit of a recipe of what can be successful against our opponents."
The Czech Republic, Finland, Sweden and Russia will play in Wednesday's quarter-finals.