The U.S. beat Colombia 3-0, Britain cruised past Cameroon 3-0 while Brazil needed a late goal to win 1-0 against New Zealand.
U.S. midfielder Megan Rapinoe opened the scoring for the Americans in the 33rd after receiving a pass from forward Alex Morgan. Rapinoe curled a shot from 20 yards and it was too high for Colombia goalkeeper Sandra Sepulveda to get her hands to.
The United States dominated possession in the first half and could have added more, but Colombia's defence did just enough to keep the Americans at bay. Colombia also caused some problems for the U.S., but conceded possession over and over again in threatening positions.
In the second half, the U.S. ramped up the pressure and scored two goals. Abby Wambach was sandwiched between two defenders in the penalty area and she was able to slide the ball past Sepulveda in the 74th. The goal made Wambach the all-time leading scorer in Olympic play for the Americans with six goals.
Carli Lloyd scored a third in the 77th. The Americans now have six points in Group G from two matches, while the Colombians have zero.
Britain advanced to the next round by beating Cameroon with goals from Casey Stoney in the 17th, Jill Scott in the 22nd and Stephanie Houghton in the 81st. Britain sits second behind Brazil in Group E on goal difference with six points.
Brazil looked as if it would have to settle for a scoreless draw against New Zealand in Cardiff, but Cristiane's winner in the 86th secured a second straight victory for the South Americans in Group E. Her high shot just made it into the net as New Zealand defenders scrambled to try keep to keep it out. Brazil's win was the polar opposite of its first match, when it crushed Cameroon 5-0.
The South American team, which is going for a first major trophy in women's football, now has six points from two matches, with New Zealand on zero points.
World champion Japan was held to a 0-0 draw by Sweden, which now tops Group F ahead of the Japanese on goal difference with four points. Japan had numerous chances, but Sweden goalkeeper Hedvig Lindahl kept the game scoreless with several key saves, especially in the second half in Coventry.
"There were some mistakes but overall they created chances," Japan coach Norio Sasaki said. "I really wanted them to have the three points but Sweden is a very good team so I am satisfied with the result."
Sweden created few chances in the second half, with Lotta Schelin's effort stopped by Fukumoto in the 70th and substitute Kosovare Asllani heading wide of the goal three minutes later.
"I am very satisfied with a point," Sweden coach Thomas Dennerby said, adding he is confident of getting through to the knockout stage.
In the second match in Coventry, Canada beat South Africa 3-0 with two goals from Christine Sinclair. Melissa Tancredi also scored. Canada is third in Group F with three points, one point behind both Japan and Sweden. The two best third-place teams advance to the quarterfinals along with the top two teams in each group.
North Korea and France play in a late match at Hampden Park.