Alex Morgan scored twice as the US women's football team rallied from an early deficit Wednesday to open its Olympics with a 4-2 win over France.
The Americans trailed 2-0 after 14 minutes, allowing more goals than they had conceded in any game since the World Cup final loss to Japan last year.
But Abby Wambach answered in the 19th, Morgan in the 32nd, Carli Lloyd in the 56th and Morgan again in the 66th in an Olympic football tournament that began two days before the opening ceremony and 400-plus miles away from London.
Football is one of two sports that starts early so it can play a full slate of games.
The Americans next play Colombia on Saturday. The French will face North Korea.
Brazil scored two early goals and got two more from Marta in the second half to easily defeat Cameroon 5-0, getting off to a good start on its quest for its first major title in women's football.
Francielle converted a free kick in the seventh minute and Renata Costa increased the lead with a header from a corner in the 10th, then Marta scored with a penalty kick in the 73rd, set up Cristiane's goal in the 80th and sealed the victory in the 88th.
The opening victory moves Brazil atop Group E with three points along with Britain.
Brazil has been close to winning a significant women's title several times but never came through with victory.
The Brazilians settled for silver in the last two Olympics.
World champion Japan scored twice in the first half then held on for a 2-1 win over Canada in its opening game.
Nahomi Kawasumi put the Japanese ahead in the 33rd minute and Aya Miyama doubled the lead in the 44th to put the favorites firmly in control at the City of Coventry Stadium.
Miyama latched on to a pass into the penalty area and produced a classy backheel to set up Kawasumi, who made no mistake with a powerful shot from close range.
Miyama then scored herself, taking advantage of a defensive mix up to angle a header past Canadian goalkeeper Erin Mclead.
Melissa Tancredi pulled one back from close range for Canada 10 minutes after the break, taking Rhian Wilkinson's low cross from the right wing and skipping in front of defender Yukari Kinga to score.
Japan, which upset the United States to win the Women's World Cup last year, started dominantly against the Canadians and only allowed a few opportunities in the first half.
Japan coach Norio Sasaki was happy with the result, although he expects an improvement in his team's next game against Sweden.
''I think it was all about the defense today,'' he said. ''We could run more than Canada and from the defense through to the attack everyone went for the ball.''
Sasaki said his team could have created even more chances.
''We could have improved and there were a lot of mistakes in the decisions for the passes,'' he said.
Canada made it more difficult in the second half with some sustained, composed play that led to Tancredi's goal.
Japan missed an early chance when Japan right back Kinga floated a ball into the box and Homare Sawa volleyed over the bar in the fifth minute.