GANGNEUNG - Four-time defending champion Canada outbattled arch-rival United States 2-1 in a heated grudge clash Thursday at the Pyeongchang Winter Games, stretching their Olympic women's hockey win streak to 23 games.

Meghan Agosta and Sarah Nurse scored second-period goals and goaltender Genevieve Lacasse made 44 saves for the Canadians in the physical group-stage contest, expected to be a preview of next Thursday's gold-medal showdown. "It's always a battle, especially against the US," Agosta said. "We know we have to keep coming. It's always going to be chippy."

Brianna Decker hit the post on a final US shot and a scramble in front of the Canada goal for the puck led to pushes, shoves and two roughing penalties well after the final horn. "We had battles in front of the net. I got shoved into the net," Lacasse said. "I just kept the puck in front me."

"It's a heated rivalry out there," Nurse added. Beating the world champions made Canada the top seed for Monday's semi-finals with the Americans second as both await Saturday quarter-final winners from among Switzerland, Finland, Sweden and the Olympic Athletes from Russia. "It puts us in a great spot as far as confidence," Canada coach Lauren Schuler said. "I'm really happy, especially with Genevieve's performance. She was outstanding." US coach Robb Stauber was pleased with his team's 45-23 shots edge and aggressive attitude. "It's a rivalry. What else would anybody expect but exactly that," he said. "We'll bring the exact same emotion the next game."

Agosta opened the scoring on the power play 27:18 into the game off a Natalie Spooner backhand centering pass and Nurse gave Canada a 2-0 edge just 7:38 later, snuggling a left-wing shot into the near corner of the net. A melee in the Canadian crease led to a US penalty shot with 3:52 remaining in the second but Jocelyne Lamoureux-Davidson's backhand was deflected over the crossbar.

"I had a lot of adrenaline," Lacasse said. "Excited and having fun out there."

Kendall Coyne breathed life into the US cause 23 seconds into the third period on a breakaway goal, skating past four defenders and beating Lacasse. "We had a lot of shots," Coyne said. "It's about finding a way to make those Grade-A chances."

Canada had a goal disallowed with 9:08 remaining in the third period when video replay review ruled Haley Irwin kicked the puck in. The Americans denied two Canada power plays late in the third period and pulled goaltender Maddie Rooney for an extra attacker in the final minute as a "U-S-A" chant went up, but they couldn't find an equaliser.