The queen visited with British Olympians in the athletes village and rode to the top of the 377-foot Orbit tower beside the stadium, where on Friday night she officially opened the 2012 Games. Her husband, Prince Philip, and London Mayor Boris Johnson accompanied her.
In describing her role in the opening ceremony, created by director Danny Boyle, Johnson said the queen had told him she was "very, very impressed with the success of her first film appearance, her first dramatic venture. It was very funny and seems to have gone down particularly well with the international audiences."
The show-stopping moment featured the queen making her acting debut alongside Daniel Craig, who portrayed James Bond in a film beamed into the stadium.
The rest of the Olympic action Saturday:
Maybe it was first-game nerves or a hangover from the opening ceremony. But the U.S. had to overcome a sloppy performance to post an 81-56 victory over Croatia in its first game.
Coach Geno Auriemma had said he was hoping the Americans could play a style of basketball that would be entertaining and help grow the women's game internationally. That didn't happen.
"We have five players who have never been in the Olympics before so they are going to be nervous. Everybody was a little nervous," Auriemma said. "We're better than we showed, but I don't know that we're going to be great right off the bat."
The U.S., which got back to its hotel at 3 a.m. after the kickoff party, struggled for the first three quarters before winning its 34th consecutive Olympic game.
Next up for the Americans is Angola, which lost to Turkey 72-50 in its Olympic debut.
The Czech Republic lost their pool opener, falling to China 66-57. In another early game, Russia rallied past Canada 58-53.
The U.S. women clinched a spot in the quarterfinals and remembered an injured teammate in a 3-0 victory over Colombia.
Megan Rapinoe scored in the 33rd minute for the Americans. After her goal, she reached into her sock and pulled out a birthday message for Ali Krieger, who blew out her knee in a qualifying match in January.
Abby Wambach made it 2-0 in the 74th, and Carli Lloyd scored in the 77th.
Britain wrapped up a spot in the women's quarters with a 3-0 victory against Cameroon. Canada beat South Africa 3-0, Brazil blanked New Zealand 1-0, and Sweden held Women's World Cup champion Japan to a scoreless draw.
The Olympics' sexiest sport opened with a raucous debut, mixing in a little local flair with all of the more traditional trifles that have made the event one of the most sought-after tickets in London (though Sir Paul McCartney managed to get one for the afternoon session).
A dance team in bathing suits — skimpier for the birds than the blokes — jiggled for the sold-out crowd during timeouts, while rock music nearly drowned out the pealing of Big Ben.
Located just inside the gate used by the queen — and only the queen — to ride up to Buckingham Palace, the beach volleyball venue offers views of the London Eye, the Big Ben clock tower and 10 Downing Street.
Americans Kerri Walsh Jennings and Misty May-Treanor, who are trying for a third consecutive gold medal, were scheduled to play in the final match on Saturday night against Australian rivals Tasmin Hinchley and five-time Olympian Natalie Cook.
The No. 2 U.S. men's team of Sean Rosenthal and Jake Gibb also were scheduled to play, taking on South Africa's Freedom Chiya and Grant Goldschmit.
Warren Buffett and Bill Gates will be thrilled when they get the news: 16-year-old American Ariel Hsing is into the second round in Olympic table tennis.
She defeated Yadira Silva of Mexico in four straight games on the opening day. With none of the top 16 players and favored Chinese entering competition until the third round, Hsing made the most of her first Olympic appearance.