The Americans thumped the Canadians 9-2 to open last year's tournament, only to suffer a 5-4 overtime loss in the final to their bitter rivals in Burlington, Vt.
The tables turned in Ottawa this year, with the U.S. losing to Canada in a shootout to open the tournament, before rebounding to win Tuesday's gold-medal game 3-2.
"Really, what matters is how to you finish the tournament," said American forward Amanda Kessel, who scored the game-winning goal. "I think we played our best game tonight."
The younger sister of Toronto Maple Leafs forward Phil Kessel pushed the U.S. ahead at 3:09 of the third period, roofing a shot on a 2-on-1 for one of two American goals scored off odd-man rushes.
That now makes for a pair of Kessels who are unpopular in Ottawa, and Amanda was unrepentant.
"It feels great," she said. "It couldn't feel any better."
The U.S. limited Canada to 16 shots on goaltender Jessie Vetter and fired 30 on Canada's Shannon Szabados, whose effort kept the host country in the game.
"If you look at the quality of chances they had compared to ours, they deserved to win," Canadian assistant captain Caroline Ouellette said. "With 16 shots on net, it's hard to win a hockey game.
The Americans have won four of the last five world women's titles and five of the last seven. Brianna Decker and Megan Bozek also scored for the U.S., which trailed 1-0 after the first period.
Courtney Birchard and Ouellette replied for Canada in front of 13,776 at Scotiabank Place.
Marie-Philip Poulin had two assists and led the tournament in scoring with six goals and six assists in five games. The 22-year-old from Beauceville, Que., was named the tournament's most valuable player and top forward.
"She was our best player from start to finish, no question," Canadian head coach Dan Church said.
Since Canada's 2-0 win over the U.S. to win Olympic gold in 2010, the teams have gone 8-8 against one another, with nine of those games decided by one goal.
The two countries have met in the finals at all 15 world championships held since 1990. Canada has won 10 times, but the Americans crept closer with their fifth overall.
The Canadian and American women will face each other at least half a dozen times next winter when both teams are training full-time for the 2014 Winter Olympics in Sochi, Russia.
A schedule of games between the teams has yet to be announced, but a Dec. 20 date in Grand Forks, N.D., has already been confirmed by USA Hockey.
The two countries are bitter rivals in women's hockey, but are each other's favourite opponents because they bring out the best in each other and make for the most entertaining games in female hockey.
Tuesday's championship game was another tug-of-war. The Americans used their superior size on the blue-line to keep Canada's shooters to the outside.
"We needed to have more sense of urgency in front of their net earlier on," Canadian captain Hayley Wickenheiser said. "We need to execute. There was no shortage of chances for us and opportunities for us, but we didn't execute."
The U.S. is overall a faster team and used its speed to pounce on turnovers and force Canada to make quick, and sometimes bad, decisions with the puck.
"Two many odd-man rushes, too many 2-on-1s," Wickenheiser said. "I don't know what we were thinking in some of the situations.
"It's tough to lose in your own country. This one stings."
Canada led 1-0 after the opening period, but Decker tied the game 1-1 on an odd-man rush, deking Szabados at 2:23 of the second.
Canada got into penalty trouble later in the period and with Rebecca Johnston and Wickenheiser serving minors, Bozek scored on a one-timer at 14:26.
But Ouellette skated out from boards and scored a power-play goal on a snapshot at 17:50 to tie it 2-2 heading to the third.
Birchard's heavy shot beat a screened Vetter at 9:50 for the only goal of the first period. Canada was outshot 12-8 in the first period and weren't able to turn 29 seconds of a two-man advantage late in the period into a second goal.
Wickenheiser was not at full health in the game. She injured her back in the first game of the tournament against the U.S. and sat out the preliminary round. She returned for the semifinal and final.
Earlier Tuesday, Russia defeated Finland 2-0 for bronze and that country's second medal in tournament history after winning bronze in 2001. The Russian Ice Hockey Federation is finally putting resources into female hockey because they want the home team to win a medal in Sochi.
Former Ottawa Senators Alexei Yashin was appointed the team's general manager in December.
Germany finished fifth and Switzerland sixth in Ottawa. Sweden, the Olympic silver medallist in 2006, avoided relegation by beating the Czech Republic in a three-game series.
There will not be a women's world championship in 2014 because the International Ice Hockey Federation doesn't hold a women's tournament in an Olympic year. Sweden will host the 2015 world women's championship. Canada will host it again in 2016 and 2020.
The field for the 2014 Olympics will include Canada, Japan, Finland, Switzerland, Sweden, Russia, Germany and Japan.
The 2013 women's world hockey championship sold about 150,000 tickets, but because they were sold in packages, actual attendance was just under 100,000, according to organizers.
The 2007 championship in Winnipeg set a tournament attendance record of 119,231 and generated a profit of $751,000 for Hockey Canada and Hockey Manitoba.
The world championship in Ottawa will make a profit of at least $500,000, according to host committee vice-chair Cyril Leeder, of which 25 per cent will go to women's hockey in Ontario and the rest to Hockey Canada's development programs.