Runner Taoufik Makhloufi was first in the men's 1,500 metres one day after he was disqualified and then reinstated after track and field officials ruled he didn't try hard enough during a heat.
The disqualification was later overturned after a medical officer reviewed the evidence, and Makhloufi made his second chance count, winning the 1,500 title in 3 minutes, 34.08 seconds.
"It was the will of God. Yesterday I was out and today I was in," Makhloufi said. "I dedicate this to all the people of Algeria and the Arab world."
The chill, dank day began with one former Olympic champion — Liu Xiang — lasting only a few meters while another — Usain Bolt — jogged gently down the track in his first steps towards a second straight golden sprint double.
Earlier, Australia's Sally Pearson set an Olympic record in the 100-meter hurdles final and gave her country its fourth gold medal of the games — and second of the day after cyclist Anna Meares was first in the velodrome's high-profile sprint.
Pearson had to wait several seconds after crossing the line in the main stadium before the big screen showed she had beaten defending champion Dawn Harper of the United States by just .02 hundredths of a second. She screamed and dropped to the ground, finally getting Olympic gold after finishing second four years ago.
In other track and field competitions on Tuesday night, Ivan Ukhov of Russia won a gold medal in men's high jump, and Ilya Zakharov of Russia won Olympic diving gold medal in men's 3-meter springboard.
The track and field finals completed a day during which Britain played the role of greedy hosts, piling on four gold medals with wins in cycling, triathlon and dressage to achieve its highest gold medal total in 104 years.
Britain ended Germany's domination of equestrian team dressage by winning the gold medal at Greenwich Park, adding to its first team show jumping gold in 60 years that it won a day earlier. Alistair Brownlee won the triathlon — his younger brother Jonathan took bronze — and British cyclists Chris Hoy won the keirin and Laura Trott the women's omnium.
It took Britain's gold total to 22, easily surpassing the 19 they won in Beijing. It's the country's best gold total since it won 56 golds in 1908 — the first time the games were held in London.
Brownlee won the men's triathlon in a time of 1 hour, 46 minutes, 25 seconds on a picturesque course through Hyde Park and The Serpentine lake.
Australia's Meares stopped the British gold rush at the velodrome when she beat Victoria Pendleton in the sprint. It was Meares who ended Pendleton's run of four straight world titles in 2011, and who Pendleton eliminated in the semifinals in May to regain her championship. It was the British veteran's final race before retiring.
In news away from the competition, Cameroon's Olympic chief said seven of the country's Olympic competitors were missing from the athletes' village, prompting concern they may attempt to seek asylum in Britain.
David Ojong, head of mission for Team Cameroon, said the seven all hold visas which would allow them to remain in Britain until at least November. He said that five boxers, a swimmer and a football player had disappeared from the village, at the Olympic Park in Stratford, east London.
On the final day of gymnastics, China's Deng Linlin won gold on balance beam, upstaging teammate and reigning world champion Sui Lu. It was the second gold of the day for the Chinese, following Feng Zhe's title on parallel bars.
Epke Zonderland won gold on high bar. American Aly Raisman took a gold on floor exercise, about an hour after getting a bronze on balance beam.
Natalia Ishchenko and Svetlana Romashina extended Russia's domination of synchronized swimming with an Olympic gold medal in duet. They haven't lost an Olympic synchro event since the 1996 Atlanta Games.
In sailing, Dorian van Rijsselberge of the Netherlands won the men's RS-X windsurfing event. The Dutch windsurfer came into the medal race with gold mathematically assured, knowing he only had to turn up and compete — even if he finished last — to clinch the victory.
Marina Alabau won Spain's first gold in the women's RS-X windsurfing race.
China's former world-record holder and 2004 Olympic champion Liu tumbled into the first hurdle and fell to the track in his opening heat, his second consecutive first-round exit in the 110-meter hurdles.
Four years ago in Beijing, Liu's Olympics ended after two full strides, when he withdrew from his preliminary heat with right foot and hamstring injuries.
Two nights after winning gold in the 100, Usain Bolt easily won his qualifying heat, glancing to his right and left as he trotted past the finish line in 20.39 seconds. That was well outside the world record of 19.19 he set at the 2009 world championships, but one that could be in danger of being broken in the semifinals and final on Thursday.
"It was good. Got to take it easy," Bolt said.
AP sports writer Dennis Passa contributed to this story.