The event was overshadowed by an hour-long delay following an appeal by the South Korean team after Heidemann's 6-5 victory over Shin A-lam in the semifinals.
South Korean officials argued the match was already over when Heidemann scored the winning point in the last second, but the jury finally upheld its decision.
Top-seeded Sun Yujie of China won bronze after beating Shin 15-11.
Danish sailor Jonas Hoegh-Christensen is proving to be much more than a one-day wonder in the Finn class in the Olympic regatta.
He's beaten British star Ben Ainslie in each of the first four races and remained in first place overall on Weymouth Bay on the English Channel.
The 49er skiffs, the fastest boats in the Olympics, made their colorful regatta debut.
Denmark's Allan Norregaard and Peter Lang were in first place with six points after the first two of 15 races.
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 late 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.
Also, 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.
Three-time Olympic champions Pavol and Peter Hochschorner finished second in the qualifying heats in the men's canoe-kayak C2 doubles competition.
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.
Australia was strong in the men's four at the rowing regatta, setting one of two Olympic-best times on a sunny final day of heat racing.
Britain, which has won this event at the last three games and is also the world champion, won the second heat and United States took the third heat.
Earlier, Britain's Katherine Grainger's quest for an elusive Olympic gold got off to a perfect start when she broke the Olympic best in the women's double sculls with partner Anna Watkins in the first heat.
China, the 2008 Olympic champion, squeezed through to the final of the women's quadruple sculls by finishing as the last of the four qualifiers in a six-boat repechage.
Defending Olympic champion Germany got off to a slow start but recovered in time to post a 2-1 victory against Belgium.
The Netherlands beat eight-time Olympic champion India 3-2 in the day's opening men's match and Australia skipper Jamie Dwyer scored a hat trick to help his No. 1-ranked side defeat South Africa 6-0.
Britain beat Argentina 4-1, and South Korea blanked New Zealand 2-0. Spain and Pakistan played to a 1-1 draw.
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 in the host's second drubbing of the tournament after its 31-19 defeat in Saturday's opener against Montenegro.
Croatia and Norway also won. France and Spain drew 18-18.
Kaori Matsumoto of Japan won the gold in the women's judo 57-kilogram division, and Mansur Isaev of Russia took the top spot in the men's 73-kilogram category.
It was Japan's first gold in London in the martial art it invented.
The women's 57K bronze medals were won by American Marti Malloy and Automne Pavia of France.
Alin George Moldoveanu of Romania won the 10-meter air rifle gold medal and tied the Olympic qualifying record, making up for narrowly missing a medal in Beijing.
Kim Un Guk won North Korea's second weightlifting gold medal at the London Games, setting a world record total of 327 kilograms in the men's 62-kilogram division, and Li Xueying grabbed China's second weightlifting gold in the women's 58-kilogram category.
China's men and women are on track to sweep the gold medals in Olympic table tennis singles.
Defending world champion Zhang Jike and teammate Wang Hao, the silver medalist at the last two Olympics, reached the men's quarterfinals Monday. For the women, top seeds Ding Ning and Li Xiaoxia are in position for a scrap over the gold medal.
Jay Cohen can be reached at http://www.twitter.com/jcohenap
- BYU basketball: NBA draft insiders weigh in...
- Live streams: 5A & 4A state baseball tournament
- Morning links: SI features Frank Jackson;...
- Doug Robinson: BYU football may be better...
- Utah Jazz: Ranking the best No. 12 picks in...
- High school baseball: Walker leads Pleasant...
- Point guard was weak spot in '14-'15, but...
- Sen. Orrin Hatch calls HBO story on dietary...
- Doug Robinson: BYU football may be... 113
- Mike Sorensen: Utah, BYU not getting a... 86
- Guest commentary: Want national... 66
- Utah Utes coaches tailor weekly... 54
- BYU's Taysom Hill, Utah's Devontae... 43
- Morning links: BYU has a shot to snap... 37
- Ranking the best quarterbacks in... 18
- BYU basketball: NBA draft insiders... 18