The second full day of competition at the London Summer Olympics Sunday saw a dramatic upset on the U.S. women's gymnastics team, and world records from U.S. and South African swimmers.
Jordyn Wieber, the world's reigning all-around female gymnastics champion, failed to qualify for the all-around finals.
Wieber wobbled on the balance beam and tumbled out of bounds during the floor exercise, coming in third behind her teammates Aly Raisman and Gabby Douglas. Countries can only have two gymnasts in the all-around final.
U.S. swimmer Dana Vollmer took the gold medal in the women's 100-meter butterfly in world record time. Vollmer, the reigning world champion, swam the 100 meters in 55.98 seconds. China's Lu Ying won the silver and Alicia Coutts of Australia took the bronze.
South Africa's Cameron van der Burgh set a world record swimming the men's 100-meter breaststroke in 58.46 seconds.
In the men's 4x100 relay, France avenged its narrow loss to the Americans four years ago by winning the gold. France's Yannick Agnel pulled ahead of American Ryan Lochte in the final lap. Lochte and his teammates won the silver medal.
With that silver medal, American Michael Phelps now has an overall Olympic medal count of 17 - one short of tying the all-time record. He won eight medals at Athens in 2004 and eight at Beijing in 2008.
Also Sunday, North Korea won its first two gold medals of the games. An Kum Ae won the women's 52-kilogram judo competition, beating Cuba's Yanet Bermoy Acosta. Om Yun Chol won the men's weightlifting gold, followed by China and Azerbaijan.
Host country Britain won its first medal - a silver in the women's cycling road race.
Georgia's Lasha Shavdatuashvili won the men's 66-kilogram judo competition.
The heavily favored U.S. men's basketball team won its opening match, beating France 98-71. Both rosters include a number of National Basketball Association stars.
After two full days of competition, China leads in the medal count with 12, followed by 11 for the United States and Italy with 7. Japan and South Korea have 5.
Monday sees one of the most anticipated swimming races - the 200-meter freestyle featuring Lochte and Agnel.
Organizers of the London games are investigating why there have been so many empty seats in the stands at multiple sporting events in the first days of competition.
Television images showed rows of empty seats at Wimbledon, the Aquatics Center and soccer stadiums. Angry fans have been complaining that they have not been able to buy tickets.
British Culture Secretary Jeremy Hunt said blocks of the empty seats were accredited to sponsors. He said if they are not going to show up, then those tickets should be made available to the public.
Photo Gallery: Day 2 of Competition