Manchester, England (Sports Network) - There was high drama at Old Trafford on Monday, but for once, it was not Manchester United producing a late goal.
The United States booked a place in the gold medal match of the 2012 Olympics as Alex Morgan's stoppage-time header in the second period of extra time gave the Americans a 4-3 win in a thriller against Canada.
Christine Sinclair netted a hat trick for Canada while Megan Rapinoe's brace and Abby Wambach's penalty saw the Americans level the score by the end of regulation.
The match appeared to be heading for penalties until Morgan's late header clinched the victory, giving the United States the opportunity to win their third straight Olympic gold medal.
The Americans will face Japan at Wembley on Thursday, a rematch of the 2011 Women's World Cup final. Japan defied the odds on that occasion, edging the United States 3-1 on penalties.
Canada took a shock lead midway through the opening period when a well-worked move was capped by a neat finish from Sinclair. Canada's all-time leading scorer collected a pass inside the box, danced past an American defender and quickly slotted a shot past goalkeeper Hope Solo.
The United States came out for the second half firing on all cylinders. The Americans put their northern neighbors under intense pressure and eventually broke through nine minutes after the restart.
Rapinoe came up big with a superb corner kick delivery, catching the Canadian defense napping and sneaking her set piece into the back of the net at the near post.
What ensued was an enthralling period of play that saw Sinclair and Rapinoe alternate goals, combining to score three times in the span of five minutes.
Canada went back in front in the 68th minute when an inch-perfect cross was met by a rising header from Sinclair, and Solo could not conjure a save.
Not to be undone, Rapinoe scored three minutes later when she ripped a shot from the corner of the box that struck the inside of the far post on its way into the back of the net.
Sinclair gave the Canadians the edge for a second time, using her head once again to get on the end of a corner kick and nod the delivery back across goal and just inside the post.
Controversy struck in the 79th minute when referee Christina Pedersen awarded the United States an indirect free kick inside the penalty area, whistling Erin McLeod for handling the ball longer than the six seconds that a goalkeeper is afforded.
Rapinoe hammered a shot on goal with the ensuing kick, which appeared to strike the arms of a couple Canadian players as the ball ping-ponged through traffic. Pedersen noticed the infraction and immediately pointed to the penalty spot.
Wambach stepped up in the high-pressure situation, slotting a shot off the left post and past McLeod for her fifth goal in her five games in the London Olympics.
The Americans nearly produced a late winner in the second period of extra time when Alex Morgan curled a beautiful cross into the box. Wambach nodded the delivery toward goal, but McLeod pushed the header onto the crossbar before the Canadian defense cleared their lines.
McLeod was helpless to stop the American train moments later as Morgan got on the end of a pinpoint cross from Heather O'Reilly to send a looping header over the Canadian 'keeper and into the back of the net.
Canada, which led a match against the United States for the first time since 2003, will play France for the bronze medal at the City of Coventry Arena on Thursday.
08/06 17:55:37 ET