Caitlin Cahow, centre, celebrates her early goal with U.S. teammates Hilary Knight and Jenny Potter as Canadian goalie Charline Labonte looks on. ((Jacques Boissinot/Canadian Press))

Canada paid the price for coming out flat on Sunday, outplayed by the United States in a 4-1 loss in the gold-medal game at the women's world hockey championships in Hameenlinna, Finland.

Caitlin Cahow scored twice as the Americans defeated Canada for the second straight year and just the third time in 12 straight meetings in the finals.

The result was such that Canada coach Melody Davidson was questioning her future afterward, despite the fact she's under contract to coach the team at the 2010 Olympics.

"If we're not going to perform in the final game, that's on my shoulders and we have to be able to perform," Davidson said. "If we can't maybe Hockey Canada has to look at a change.

"There's no excuses for that performance out there today."

Cahow scored just 24 seconds into the game and added an insurance marker in the third as the Americans defeated Canada in the final for a second consecutive year.

The Americans led for nearly 55 minutes in Sunday's game. After Jennifer Botterill tied the game 1-1 in the second, Meaghan Duggan broke the tie just five minutes later.

After Cahow's second goal, Hilary Knight drew her second assist of the game on Julie Chu's empty-netter with nine seconds left.

"Any time you win a world championship is pretty great and to have that feeling two years in a row, there's nothing like it," U.S. captain Natalie Darwitz said.

"It's going to be a lot different [at the Olympics] next year. The stakes are going to be higher."

Goalie Jessie Vetter, named top U.S. women's college hockey player recently, has not lost in her last four games against Canada. She finished with 25 saves.

Twin sisters Monique and Jocelyne Lamoureux, as well as Jenny Potter, also played strongly for the winners, coached by former U.S. Olympic and NHL player Mark Johnson.

Charline Labonte prevented Canada from falling further behind in the first two periods, making 19 saves in the game.

St-Pierre sits out

Canadian coach Melody Davidson opted to start Labonte over Kim St-Pierre, who recorded shutouts in wins over Finland and Sweden.

Potter fed Cahow with a cross-ice pass to the slot just after the opening face off, with Labonte having no chance on the play.

"We knew we had to do something special on the first shift," Cahow said. "I don't know how Jen made that pass through skates and sticks, but it was an easy touch-in for me."

The Americans continued to apply the pressure for much of the period, with Labonte holding firm on Monique Lamoureux's shot.

Vetter did her part on a strong chance from Gillian Apps late in the period.

Monique Lamoureux had another chance early in the second, picking up a loose puck in the slot but firing it right into Labonte.

Jennifer Botterill scored from the slot early in the second after a nice setup from Caroline Ouellette. Jayna Hefford also assisted and provided an effective screen of Vetter.

The Americans replied quickly as Jocelyne Lamoureux thread the needle on a pass to Meaghan Duggan, who picked the top corner over Labonte's glove.

Slot shot scores

Gigi Marvin had Labonte down and out on a U.S. power play early in the third but couldn't lift the puck. Just seconds later, however, Cahow fired a shot from the slot between Labonte's pads.

Canada could not rally, with Meghan Agosta's wraparound providing the best opportunity.

"I felt we were ready and I'm not sure why we didn't perform," Davidson said. "We tried hard, but we didn't necessarily work hard enough. We didn't work through the scrums. We didn't work through the battles."

Each team ran roughshod over the competition throughout the week. Canada beat the U.S. 2-1 on Friday, a game that meant little in the event standings but was played with much pride.

In addition to the two world championship defeats to the U.S., Canada was upset by Sweden in the Four Nations Cup in November.

The results should serve as plenty of motivation as the Canadians try to win a third straight Olympic gold medal in Vancouver in 2010.

In addition to the Four Nations and a Canada Cup tournament in August, Canada and the U.S. will intensify their rivalry six times in an exhibition series later this year. Victoria, Calgary and Ottawa will host the games taking place in Canada.

Finland captured the bronze in front of their home fans earlier Sunday, defeating Sweden 4-1. Michelle Karvinen scored twice for the winners, who broke open a one-goal game in the third period.

With files from The Canadian Press