The 2012 Olympic women's soccer semifinal between Canada and the United States was played at Old Trafford in Manchester, England, on 6 August 2012.

[6] Canada opened the group stage of the tournament on 25 July against Japan, who was coming off victory in the 2011 FIFA Women's World Cup.

After a slow start to the game, Canada pulled a goal back in the 56th minute as Melissa Tancredi scored, but the match ended 2–1 in favor of Japan.

In the 12th minute, Sophie Schmidt took a corner kick and her ball found Jonelle Filigno, who fired a half-volley shot past British goalkeeper Karen Bardsley for the first goal of the match.

[12] They opened the group stage on 25 July at Hampden Park against France, who they had defeated in the semifinals of the previous year's World Cup.

France, who had won 17 straight games entering the contest, scored twice in the opening 15 minutes, on goals by Gaëtane Thiney and Marie-Laure Delie.

In the 27th minute, a right-footed cross from Morgan found Wambach, who slotted the ball past New Zealand goalkeeper Jenny Bindon to give the U.S. the first goal of the game.

The score remained the same until the 87th minute, when U.S. substitute Sydney Leroux finished a counterattack by hitting a right-footed shot into the corner of the net, a goal that clinched a 2–0 U.S. win and a spot in the semifinals against Canada.

[16] Writer Cathal Kelly described the early play as "a grind",[17] as Canada sought to employ physical defending against the U.S.[6] In the 22nd minute,[3] a Canada move saw Sinclair receive a pass from Marie-Ève Nault and spin to create space in the box, where her shot beat U.S. goalkeeper Hope Solo for the match's first goal.

[16][18] Following the goal, Canada's midfielders began having more success beginning attacks, with less pressing from U.S. defenders than in the early stages of the game.

Just before halftime, Lauren Cheney attempted a long-range chip shot, having noticed that Canada goalkeeper Erin McLeod was off her line, but it also went wide of the goal.

[16] The U.S. had a chance to equalize early in the second half, as a 51st-minute cross from Morgan found Wambach, whose volley attempt went over the goal.

Diana Matheson's effort found Sinclair, who beat the U.S. defenders to the ball and fired a strong header into the corner of the goal.

[16][18] McLeod had not officially received a warning in the game, but the topic of speeding up her taking of kicks had been brought up to her by an assistant referee during halftime.

[17] Wambach had started loudly counting the seconds McLeod was holding the ball in an effort to draw the referee's attention.

[16] In the second period of extra time, the teams maintained what The Guardian's Graham Parker called "high octane intense soccer.

"[16] Wambach nearly had a potential game-winning goal in the 119th minute, when Morgan delivered a cross for her to hit a looping header while leaning back, but the attempt went off the crossbar.

[16][17] Assistant referees: Hege Steinlund (Norway) Lada Rojc (Croatia) Fourth official: Hong Eun-ah (South Korea) Following the game, The Guardian's Scott Murray called the U.S.–Canada semifinal "the greatest knockout match in major-tournament football" since the 1982 FIFA World Cup semifinal between West Germany and France.

"[19] A few years after the game, Kelly referred to Canada's defeat as "perhaps the most mythic, vexing, and binding" one a Canadian team had suffered.

Murray remarked that "nobody in any form of professional football has been pulled up for [holding the ball] since the days crossbars were made out of tape".

"[22] Following the semifinal round, she received a four-match ban from FIFA for "unsporting behaviour"; the suspension was due to comments directly made to an official after the game.

U.S. head coach Pia Sundhage resigned in the months following the Americans' win, to accept the same position with the national team of her native Sweden.