SHANGHAI, China (AP) -- Natasha Kai headed in an extra time goal Friday to give the defending champion United States a spot in the Olympic women's football semifinals after a 2-1 victory over Canada.
Angela Hucles gave the Americans a 12th-minute lead from in close at the Olympic Stadium.
But Christine Sinclair replied in the 30th for Canada with a powerful 22-meter shot in a game which was suspended for 1 hour, 40 minutes during the first half because of lightning.
The extra time and the thunderstorm meant the game took 4 hours and 10 minutes to complete.
Now Pia Sundhage's team moves on to try and maintain its record of reaching every Olympic final. The U.S. won in 1996 in Atlanta, was runner up to Norway at Sydney 2000 and won again in Athens in 2004.
The coach was pleased that her team kept trying to score even after Kai's goal in the 101st minute.
"With this young team it's healthy that they tried to score another goal," the Swede said. "I'm not opposed to that. I thought they did well."
Shannon Boxx, who provided the cross for the winner in her 100th game for the team, said it had become used to winning tight matches.
"All year this team has been great at dealing with pressure, either being down a goal or tied of having a team come back," she said. "We've always fought for 90, 100, whatever it takes. I like the fact that we are creating chances and having different people score goals."
Canada coach Even Pellerud, who is stepping down after this match after nine years in charge, was disappointed his team allowed the Americans to play their passing game.
"I hoped to see my team play as well as they have done before this tournament. We didn't," he said.
"We gave the U.S. team too much time and space to use their passing skills. Normally playing the U.S. brings out the best of us but today we looked a bit tired and didn't have the legs or gas we used to have. They created more than we did."
The thunderstorm that sliced the first half in two started right on kickoff time and soon the players were playing in torrential rain.
But it didn't stop the Americans going ahead with a simple move in the 12th minute,
Amy Rodriguez' cross from the right was headed down by Heather O'Reilly and, although Canadian goalkeeper Erin McLeod partially blocked it, Hucles was perfectly positioned at the far post to nudge the ball over the line.
Eight more minutes were played in awful conditions with thunder and lightning rumbling and flashing around the stadium before the referee, on the advice of the organizers, took the players off for their own protection. It was also a minute after Canada had been forced to replaced an injured goalkeeper, Karina LeBlanc taking over from McLeod.
Technically superior, the Americans created better chances but were shocked by an equalizer after 30 minutes.
They lost possession just outside their own area, Clare Rustad won the ball and Sinclair took over, firing a 22-meter shot that flew past goalkeeper Hope Solo inside the far post.
Hucles should have made it 2-1 in the 34th when she had only goalkeeper LeBlanc to beat from 12 meters but pulled her shot well wide of the far post.
When Hucles got clear again in the 71st minute, she went for goal but shot straight at LeBlanc.
The Canadians rarely threatened but Sinclair went close to snatching the lead in the 79th with a low left-foot 22-meter that Solo saved well one-handed diving to her left.
Extra time was 11 minutes old when the Americans edged ahead again. Shannon Boxx sent in a looping cross from the left and Kai, who replaced Heather O'Reilly at the start of the first extra period, got behind the Canadian defense to head past the exposed LeBlanc from five meters.
Substitute Lauren Cheney should have made it 3-1 when Kai ran down the left and gave her a clear shooting chance, but she shot wide.