Michael Phelps stormed to a 20th Olympic Games medal on Thursday while British cyclist Chris Hoy claimed a record-equalling fifth career gold to top off a memorable day for the hosts.
Phelps won the 200m individual medley to become the first man to take the same individual swimming gold at three straight Games.
The US star, denied trebles in London in the 400m medley and 200m butterfly, delivered a vintage performance to win in 1min 54.27sec and collect his 20th career Olympic medal -- and his 16th gold.
"It is a relief to win an individual gold. I fell short in the first couple of events, it is cool to do something no other male swimmer has done," said Phelps.
American Rebecca Soni broke the women's 200m breaststroke world record for the second time in two days while compatriot Tyler Clary won gold in the men's 200m backstroke, denying team-mate Ryan Lochte a repeat victory.
Ranomi Kromowidjojo of the Netherlands prevented an American swim sweep by taking gold in the women's 100m freestyle.
World 100m freestyle champion James Magnussen's Olympic debut suffered another miserable outing when the Australian failed to make the final of the men's 50m freestyle.
On a wild day of records and controversy at the London Velodrome, track cycling king Hoy equalled former rower Steve Redgrave's British record haul of five golds after winning the men's team sprint.
Hoy's Britain clocked their second world record of the night to successfully defend their Beijing 2008 title in the final against France as they were roared to the line by a packed home crowd.
Philip Hindes, Jason Kenny and Hoy completed their three-lap effort in a new world mark of 42.600sec, beating the record of 42.747 they had set earlier in qualifying.
"We knew it was possible. This didn't just come out of the blue, but we knew if we kept it together, we had to have the best possible race," said Hoy.
Germany's Miriam Welte and Kristina Vogel were crowned women's team sprint champions in controversial fashion following the relegation of China.
Guo Shuang and Gong Jinjie had combined to claim what appeared to be a first ever Olympic cycling title for China, only to be demoted to the silver medal position for an infringement in the changeover zone.
Guo and Gong had earlier underlined their credentials by twice setting a new world record for the two-lap power event in 32.447 and 32.442.
Britain moved into fifth place in the medals table, above traditional superpower Russia, who had President Vladimir Putin on hand to cheer on a gold medal-winning judoka Tagir Khaibulaev.
Britain captured three golds and three silvers on a day when 18 titles were up for grabs.
Peter Wilson claimed Britain's first Olympic shooting medal for 12 years in the double trap while Tim Baillie and Etienne Stott edged out compatriots David Florence and Richard Hounslow in canoe slalom.
Britain's other silvers came in the women's -78kg judo from Gemma Gibson, and their men's lightweight fours rowing team.
China's 18th gold of the Games came courtesy of Zhang Jike in men's table tennis.
The United States' women were busily setting records.
In gymnastics, 16-year-old Gabby Douglas became the first black woman to win the women's individual gymnastics gold while Kayla Harrison made history by winning the first ever gold in judo for America with her win over Gibbons.
Harrison, who was sexually abused by her former coach as a teenager, paid tribute to her current trainers -- the father and son team both called Jimmy Pedro -- for helping him move on from her past.
"It's no secret that I was sexually abused by my former coach, it was definitely the hardest thing I've had to overcome," she said. "I couldn't have done it without the support of the Pedros, my team-mates, my family.
"This gold represents years of hard work not just by me but my coaches. Big Jim has been doing judo for over 40 years. We've all made sacrifices."
The US Dream Team set a new Olympic record score by defeating Nigeria 156-73 as Carmelo Anthony scored a game-high 37 points on 10-of-12 shooting from 3-point range. All of those figures were US Olympic team records too.