Alex Morgan netted twice to open the game up as the USA took a big win late.
A record crowd of 22,453 provided the backdrop at the stadium as the Olympic medal winning teams battled in the highly anticipated game, but in the end the world no.1 ranked Americans were simply too much to handle.
The first half started off a bit sloppy, as both teams looked a bit overawed by the occasion. The Americans quickly took control of the match though, with the visitors calmly stroking the ball around the back looking for any openings in Canada's defense.
The hosts were steadfast however, delivering crunching tackles whenever the ball got too close to goalkeeper Erin McLeod's 18-yard box.
This pattern continued for some time, as Canada looked to counterattack with quick outlet passes to front line duo Christine Sinclair and Melissa Tancredi. Predictable at first, the Canuck strategy proved increasingly effective as the half wore on, as Canada looked its most dangerous in the closing stages of the first half.
Unfortunately for the raucous BMO Field crowd, the best chances for either side in the opening 45 could hardly be considered dangerous opportunities, as neither team looked particularly threatening going forward.
the highlight of the first half was the crowd itself, which counted in unison the number of seconds every time U.S. 'keeper Nicole Barnhart held the ball in her hands. This was, of course, in reference to American striker Abby Wambach visibly doing the same against Canada at last year's contentious Olympic semifinal.
The second half started just as tentatively as the first, but the teams took less time to settle down. It was again the Americans that looked the more threatening of the two sides, and in the 52nd minute they nearly got on the board though superstar forward Alex Morgan.
The U.S. striker shook free of her defender and barreled in on goal, but Canadian defender Kadeisha Buchanan tracked her run and delivered a perfectly timed tackle from behind to prevent a point blank attempt on goal.
The American pressure continued, and a few moments later Lauren Cheney nodded a cross goal bound. Her low effort seemed destined for the Canadian net if not for a last-ditch effort by the Canuck defense, which had formed a barrier on the goal line.
Morgan's pace would cause the Canadian back line fits throughout the second half, with the 23-year-old getting in behind the hosts' defenders and sending in dangerous ball for her teammates. McLeod was equal to everything to Americans could throw at her until the 70th minute, when Morgan finally was able to break the deadlock with a well-place shot from the left flank.
Two minutes later, Morgan doubled her own tally and the the lead with a nearly identical run and finish down the left side, completely changing the complexion of a game that Canada had grown into just minutes previously.
The rest of the match was academic, as play settled back down following the Morgan strikes. The Canadians would have a couple of moments of good possession though, and in the 90th minute Tiffany Cameron came agonizingly close to getting Canada on the board after a cross eluded teammate Kaylyn Kyle and fell to her feet.
Cameron's shot was just wide as she was put under pressure by an American defender at the right moment.
To add insult to injury, as Canada was pressing for a consolation goal in injury time, Canadian-born Sydney LeRoux was sent in alone on a counterattack and potted the third, ending a frustrating afternoon for the home side.