The Chinese won their second consecutive Olympic title in gymnastics and third in four games after a dismal performance in qualifying.
China’s score of 275.997 points was more than four points better than Japan, which needed help from a replay to finish second.
Britain initially was announced as the silver medalist. The British don’t have a proud history in gymnastics, and this was their first men’s team medal in a century.
But Japan questioned the score of three-time world champion Kohei Uchimura on pommel horse, the very last routine.
About five minutes later, Uchimura’s score was revised, with judges giving him seven-tenths more credit for his dismount. Instead of 13.466, he scored 14.166 — enough to move Japan from fourth to second with a total of 271.952. Britain was bumped down to bronze, with the U.S. finishing fifth.
Serena and Venus Williams each advanced in the singles tournament, then combined for a doubles win.
Other major champions to advance in singles included Roger Federer, Lleyton Hewitt, top-seeded Victoria Azarenka, Kim Clijsters, Petra Kvitova, Ana Ivanovic and three-time Wimbledon runner-up Andy Roddick.
Switzerland stripped a soccer player of his Olympic accreditation after he sent a threatening and racist message on Twitter about South Koreans. The comments by Michel Morganella, 23, came hours after the Swiss lost 2-1 to South Korea on Sunday.
The player said in the tweet that South Koreans “can go burn” and referred to them as a “bunch of mongoloids.”
Candace Parker had 14 points and 12 rebounds to help the United States to a 90-38 rout against Angola.
The Americans (2-0) have won their last 35 games in the Olympics and four consecutive gold medals while Angola is looking for its first victory.
France had the most surprising win of the day, edging Australia 74-70 in overtime. Emilie Gomis scored all 22 of her points after halftime.
China, Turkey, Russia and Canada also won.
Maggie Steffens scored seven goals to lead the U.S. women’s team to a 14-13 victory over Hungary.
Russia spoiled Britain’s Olympic debut in women’s water polo, getting a late breakaway goal from Evgeniya Ivanova in a 7-6 win. Spain and Australia won their matches.
Cao Yuan and Zhang Yanquan totaled 486.78 points in the men’s 10-meter synchronized platform, giving China its second gold medal in the sport at the games.
German Sanchez and Ivan Garcia of Mexico had the highest degree of difficulty in the competition and it paid off with the silver.
Nick McCrory and David Boudia of the U.S. took the bronze with 463.47.
Top-seeded Lee Chong Wei returned from an injury break to squeak into the last 16 of the Olympic tourney.
The Malaysian, who tore right ankle ligaments at the Thomas Cup in May, beat Ville Lang of Finland 21-8, 14-21, 21-11.
Defending champion Lin Dan of China eased through his opener against Scott Evans of Ireland 21-8, 21-14. For the women, world champion Wang Yihan and No. 2-seeded Wang Xin also advanced with ease.
Wang Yihan opened her first Olympics with a 21-8, 21-16 win over Michele Li of Canada, and Wang Xin beat Rena Wang of the United States 21-8, 21-6.
Fencer Yana Shemyakina of Ukraine beat defending champion Britta Heidemann of Germany 9-8 to win the Olympic gold medal in women’s individual epee.
Top-seeded Sun Yujie of China won bronze after beating Shin A-lam of South Korea 15-11.
Three-time Olympic champions Pavol and Peter Hochschorner finished second in the qualifying heats in the men’s canoe-kayak C2 doubles contest.
The Slovakian twin brothers, seeking a fourth consecutive Olympic gold, qualified behind the French pair of Gauthier Klauss and Matthieu Peche.
In the women’s K1 singles, Maialen Chourraut topped the qualifying in 98.75. Britain’s Lizzie Neave was second, only 0.17 behind.
Russia and Brazil in Group A and South Korea in Group B lead the women’s handball competition after two rounds with two wins apiece.
Title favorite Russia routed Britain 37-16. Croatia and Norway also won. France and Spain drew 18-18.