GANGNEUNG, Korea, Republic Of -- Laura Schuler is keeping everyone guessing about her goaltending.

The head coach of Canada's women's hockey team started all three of her goalies in the preliminary round of the Winter Olympics.

Genevieve Lacasse's 44 saves in a 2-1 win over the United States on Thursday helped the Canadians go undefeated in their three Pool A games.

The U.S. dropped to 2-1, but both countries were already destined for Monday's semifinals having won their first two games of the tournament.

Veteran netminder Shannon Szabados had 22 saves in Canada's 4-1 win over Finland on Tuesday. Ann-Renee Desbiens posted an 18-save shutout against the Olympic athletes from Russia in her Olympic debut Sunday.

"We're going to definitely have some tough decisions," Schuler said Thursday. "All three continue to show they can play in big games for us."

Canada will play the winner of a quarter-final between the Russian team and Switzerland in the semis, while the Americans play either Sweden or Finland.

It's a tactical advantage for Canada in the medal round if the opposition is guessing which goalie they'll face.

After a scoreless first period Thursday, Canada's Meghan Agosta scored a power-play goal at 7:18 and Sarah Nurse followed even-strength at 14:51.

Lacasse denied Jocelyne Lamoreux-Davidson on a penalty shot at 16:08.

Kendall Coyne beat Lacasse between the pads 23 seconds into the third, but the Americans didn't muster another goal despite outshooting Canada almost 2-to-1.

American goaltender Maddie Rooney turned away 21 of 23 shots.

"We hit a lot of posts, we had a lot of chances and we're not going to worry about the scoreboard," U.S. coach Robb Stauber said.

"We're going to worry about the things that we think are going to give us the best chance of winning and that's the kind of performance we had tonight.

"I have no doubt our players will be rewarded for that kind of energy and effort."

Officials waved off a pair of Canadian goals in the game and reviewed a game-ending scrum for a potential U.S. goal before letting the score stand.

With her 16th goal in her fourth Olympics, Agosta moved into second all-time behind Canada's Hayley Wickenheiser (18).

"I didn't even know about it until someone mentioned it to me before the tournament," Agosta said. "It's not in my vision. That's not what we're here for. We're here to win a gold medal."

One of the most storied rivalries in sport has only gained in intensity in recent years.

Canada may have won four straight Olympic gold medals, but the United States has claimed seven of the last eight women's world championships, beating Canada in the final for every one.

Canada went 5-1 against the Americans in a six-game exhibition series this winter, although the U.S. beat Canada twice to win November's Four Nations Cup tournament in Florida.

Thursday's game was their first meeting since Canada edged the U.S. 2-1 in overtime Dec. 17 in Edmonton.

Both teams were clearly fatigued in that game as players on both sides were in full-fledged training mode.

They hadn't started their taper to peak for the Games then, but their gas tanks were full Thursday.

"It hit another level compared to our game previous," Nurse said.

Canadian forward Haley Irwin was whistled for closing her hand on the puck in a goal-mouth scramble late in the second period.

Lacasse deflected Lamoureux-Davidson's penalty-shot attempt.

"I just kept my eye on the puck," said Lacasse. "(She) pulled it through her legs, tried to do something fancy and I just watched it and pushed over and made the save. I didn't wink. I just looked at her."

Canada had some shaky line changes in the first period, requiring Lacasse to stop an all-alone Hilary Knight from close range four minutes into the game.

Schuler wasn't overly concerned about giving up over 40 shots.

"I'm going to look at game film here real closely over the next couple of days," the coach said. "Obviously you always want to eliminate shots against.

"For me, most importantly, I'll look at scoring chances for and against and how can we generate more and how can we eliminate some of those chances against us."

The Olympic hockey schedule has all teams, men's and women's, starting games at varied hours.

The Canadian women have had puck-drops at 9:10 p.m. and 4:40 p.m. and Thursday's game started just after noon local time.

"Throughout the year, we actually have made sure with our game times and our practice times that we varied them," Schuler said.

The women played their final exhibition game before the Games -- against a university men's team in Incheon, South Korea -- at 10 p.m.