It would appear that there is no limit to the number of knockout punches the U.S. women's national team can take. On a night when Canada attacker Christine Sinclair played a game for the ages by scoring a hat trick, the Americans' never-say-die attitude once again proved the difference, as Alex Morgan's header in the waning moments of extra time saw them prevail 4-3 in an enthralling Olympic semifinal.
Megan Rapinoe scored twice for the U.S., while Abby Wambach converted a contentious penalty to even the match late.
The U.S. will face World Cup nemesis Japan in the final, while Canada will take on France for the bronze medal.
It was a result that was as bitter for Canada as it was euphoric for the Americans. Canada took the lead on three occasions through the incomparable Sinclair and gave as well as it got throughout this epic match. In addition to tenacity, some luck was on the Americans' side. Rapinoe's first goal -- straight in from a corner kick -- was utterly preventable. Canada will also shake its heads over the penalty that led to Wambach's equalizer, as Canadian defender Marie-Eve Nault appeared to have her arms close to her chest when Rapinoe's shot struck her in the elbow. That didn't stop the ref from calling a handball.
That said, it's practically expected for the Americans to wage extraordinary comebacks. This time, it was Morgan who scored the game winner, as she nodded home substitute Heather O'Reilly's cross deep into stoppage time of the second extra period.
In a decision befitting two teams on a roll, both managers named unchanged sides from their quarterfinal triumphs. It had been 11 years since Canada had beaten the U.S., a span of 26 games, giving the Americans a mental edge. Canada manager John Herdman ratcheted up the prematch gamesmanship when he accused the U.S. of illegal tactics on set pieces.
Duly motivated, the U.S. set about dominating the first 20 minutes, especially in midfield, where the Americans were pouncing on every loose ball and launching a barrage of crosses into the box. Canada could barely get the ball out of its own half.
Yet it took just one lapse in defensive concentration by the Americans for Canada to go ahead in the 23rd minute. The U.S. had done a good job of shackling Sinclair in the early going, but Canada caught the U.S. defense out of shape thanks to Nault's run forward. Her entry pass to Melissa Tancredi saw the Canadian forward pick out Sinclair's late run, and after evading a challenge from Kelley O'Hara, Sinclair slotted her low shot easily past Hope Solo in the U.S. goal.
The score stayed 1-0 until the 54th minute, when the Americans scored what can only be described as fluke goal. As Rapinoe prepared to take a corner, Canada's Desiree Scott abandoned the near post to apply a double-team to Morgan. The U.S. midfielder's ensuing delivery proceeded to sneak inside the goal in precisely the area Scott had vacated.
It appeared that order had been restored, but nothing of the sort took place. Sinclair put Canada back ahead in the 68th minute when she nodded home Tancredi's cross from the left wing, only for Rapinoe to score her second equalizer of the night two minutes later with a bullet shot from just inside the penalty area.
Sinclair wasn't done, completing her hat trick in the 73rd minute when she soared over Rachel Buehler to head home Sophie Schmidt's corner.
U.S. manager Pia Sundhage then pulled Amy LePeilbet for Sydney Leroux in the 76th minute and went to a 3-4-3 formation. Yet no amount of tactical planning could have predicted the manner of the U.S. equalizer just three minutes later. Canada goalkeeper Erin McLeod was whistled for time wasting and after Rapinoe's ensuring free kick was deflected into the arm of Nault who was whistled for handball and penalty. Even more galling to Canada is that the play looked to be quite similar to an incident involving Rapinoe earlier in the half that went uncalled. After a lengthy wait, Wambach dispatched the spot kick off McLeod's right hand post and the U.S. was level.
An already open match was end-to-end thereafter. Wambach put Morgan's low cross agonizingly wide in the 85th minute. At the other end, Schmidt's tackle on Buehler allowed the Canadian to go in alone on goal, but Solo delivered a splendid save with her feet to keep the game tied.
The chances dried up somewhat in extra time, although there was no letup in intensity. Leroux had a shot from close range in the 99th minute that went over the bar. Sinclair had a bid for a fourth goal five minutes later, only to be denied by a last-ditch challenge from Buehler.
The U.S. came within inches of winning the match in the 119th minute. Rapinoe's long pass released Morgan into space on the left wing. Her cross resulted in a floating header from Wambach that went off the crossbar with the help of the faintest of touches from McLeod.
That proved to be a mere prelude to Morgan's heroics, and the U.S. was left to celebrate a victory that will live long in the annals of the women's Olympic tournament.
Now the U.S. is set to take on Japan, which delivered some stellar comebacks of its own last year to thwart the Americans' World Cup bid. Without question, Sundhage will want to address her side's defensive shortcomings in this game, which were many, but with a U.S. attack spearheaded by Wambach and Morgan, the Americans have to like their chances to claim their third consecutive gold medal.
Player rating: (0-10; 10=highest)
G Hope Solo, 6.5 -- Yes, she allowed three goals, but she had no chance on any of them and delivered a clutch save from Schmidt late.
D Kelley O'Hara, 3 -- Her inexperience as a defender was exposed in this match. Her poor positioning contributed to Canada's first goal, as O'Hara didn't shift over with the rest of her teammates. Got forward to good effect per usual -- her long pass set up Rapinoe's second goal -- but was cleanly beaten in the air on Sinclair's second tally.
D Rachel Buehler, 4 -- Her play was all over the place. She defended well for long stretches, but her performance eroded significantly. She was beaten for Sinclair's third goal, only to rally late with some clutch tackles.
D Christie Rampone, 4.5 -- Used her speed to good effect but was skinned by Tancredi on the wing for Sinclair's second.
D Amy LePeilbet, 5 -- Defended tough and did what she could to get into the attack but needed to say on her post instead of creeping forward on Sinclair's third tally.
M Tobin Heath, 7 -- Had some great touches in the attacking third and provided plenty of defensive pressure.
M Carli Lloyd, 6.5 -- Made some surging runs forward as well as some dead-eye long passes. Did what she could to contain Sinclair in the center of the park.
M Lauren Cheney, 5 -- Failed to track Sinclair's run on Canada's first goal, and while she made herself available in the middle, she didn't have much influence.
M Megan Rapinoe, 8 -- Delivered a barrage of crosses in the opening minutes, but none found the target. Her two goals proved massive, however, and while her first goal owed itself to some good fortune, her second was brilliant.
F Abby Wambach, 6.5 -- Was shackled by Canada's defense for much of the match, but penalties don't come any more pressure-packed and she delivered.
F Alex Morgan, 7 -- Her finishing touch continued to elude her for much of the match, but her work rate was phenomenal and her link play was excellent. Her hard work paid off with a priceless goal in added time of the second extra-time period.
F Sydney Leroux, 6.5 -- Threatened with her speed and toughness.
M Heather O'Reilly, 7 -- Was active on the flank, forcing a few corners, and delivered a magic cross in extra time for Morgan's goal.
D Becky Sauerbrunn, 7 -- Did well to take charge on a dicey ball into the box late and was smart with her positioning.
Jeff Carlisle covers MLS and the U.S. national team for ESPN.com. He is the author of "Soccer's Most Wanted II: The Top 10 Book of More Glorious Goals, Superb Saves and Fantastic Free-Kicks." He can be reached at firstname.lastname@example.org.