At the Velodrome, Chris Hoy hailed his fifth Olympic Games gold as his best ever, after Great Britain's men's Team Sprint squad triumphed on a night of high drama.
Having set a world record in the first round, Hoy, Philip Hindes and Jason Kenny promptly clocked another in a stunning finale, finishing in 42.600.
In a repeat of the final four years' ago at Beijing 2008, France's Gregory Bauge, Michael D'Almeida and Kevin Sireau had to settle for silver, finishing in 43.013, with Germany third.
Hoy said: 'When I crossed the line, I didn't have to look at the scoreboard, I knew we'd won. I thought my first win in Athens was the most memorable for me, but this by far is my greatest win.'
Germany's Miriam Welte and Kristina Vogel had earlier won gold in the women's Team Sprint, but only after China were relegated for a takeover offence. Australia's Anna Meares and Kaarle McCulloch (32.727) claimed bronze ahead of Ukraine.
Britain's men's Team Pursuit squad also set a world record. The quartet of Ed Clancy, Steven Burke, Geraint Thomas and Peter Kennaugh - who set the world record in winning April's Track Cycling World Championships in Melbourne - went 0.796 seconds faster, clocking 3:52.499.
South Africa's rowers clinched Olympic gold in the men’s Lightweight Four at Eton Dorney after prevailing in a thrilling finish. They, Great Britain and Denmark were all in contention in the final 50 metres but the quartet of James Thompson, Matthew Brittain, John Smith and Sizwe Ndlovu just did enough to cross the line first. Britain managed silver with Denmark coming third.
The United States retained their Olympic title in the women's Eight to continue their dominance of the event. The USA, five-time world champions and unbeaten since 2006, beat Canada into silver with the Netherlands taking bronze.
New Zealand duo Nathan Cohen and Joseph Sullivan won the men's Double Sculls final ahead of Italy and Slovenia.
It was a wonderful night for the United States in the pool with Michael Phelps, predictably, leading the way by claiming his 20th Olympic Games medal - and his first individual gold of the meet - in the 200m Individual Medley.
Phelps led from start to finish and held off fast-finishing team-mate Ryan Lochte down the final freestyle leg to win in 1:54.27, just 0.04 seconds outside his own Olympic record.
It means Phelps is the first man to win the event at three consecutive Games and comes just 48 hours after he won his 18th and 19th Olympic medals to overtake Soviet Union gymnast Larisa Latynina, who held the previous record with 18.
Lochte took silver in 1:54.90, with Hungary's Laszlo Cseh taking bronze.
Another American, Rebecca Soni, claimed gold in the women's 200m Breaststroke after smashing her own world record in the final.
The 25-year-old took control of the race after the opening length and touched in a time of 2:19.59, taking more than four tenths of a second off her previous best, set in the semis. Japan's Satomi Suzuki claimed silver with Russian Iuliia Efimova taking bronze.
Team USA's Tyler Clary surprisingly got the better of Lochte in the 200m Backstroke. Lochte led at the final turn but faded in the closing 50m, allowing Clary to snatch victory in a new Olympic record of 1:53.41, with Japan's Ryosuke Irie claiming silver.
Ranomi Kromowidjojo of the Netherlands ensured there would not be an American clean sweep of the evening's four finals, powering to victory in the 100m Freestyle and lowering her Olympic record - set the day before - to 53.00.
The 21-year-old stormed down the final length to finish ahead of Aliaksandra Herasimenia and China's Yi Tang.
At Wimbledon, Andy Murray beat Nicolas Almagro to set up a men’s Tennis Singles semi-final clash with Novak Djokovic, who beat Jo-Wilfried Tsonga.
The other semi will see world number one Roger Federer take on Juan Martin Del Potro.
In the women's event, Serena Williams will take on Victoria Azarenka in the last four while Maria Sharapova will meet Maria Kirilenko in an all-Russian clash.
Italy's version of the 'Dream Team' did what was expected of them by adding Team Fencing gold to the three individual medals they won on Saturday in the women's Foil.
Valentina Vezzali, Elisa Di Francisca - now a double gold medal-winner in London - and new world number one Arianna Errigo were in unstoppable form all day and took the title with a 45-31 victory over Russia.
For 38-year-old Vezzali, Italy's flag-bearer at the Opening Ceremony, it meant a sixth gold of her glittering career - and that equals the Italian record of fellow fencers Edoardo Mangiarotti and Nedo Nadi.
Hosts Great Britain claimed two more gold medals in the space of five minutes this afternoon.
First Etienne Stott and Tim Baillie led a British one-two in the two-man Canoe Slalom - David Florence and Richard Hounslow finishing second - before shooter Peter Wilson claimed the men's Double Trap title.
World record holder Wilson finished two clear of Sweden's Hakan Dahlby with a total score of 188 out of 200 shots fired. Russian Vasily Mosin won bronze after a shoot-off with Kuwaiti Fehaid Aldeehani.
Germany's Dimitrij Ovtcharov delivered Europe's first singles Table Tennis medal in 12 years by claiming bronze with a 4-2 defeat of Taiwan's Chuang Chih-yuan.
Zhang Jike took the gold and, in the process, completed the Grand Slam as Wang Hao endured more Olympics heartache at the London 2012 Games.
Wang, the silver medallist in Athens and Beijing, lost 4-1 as Zhang became just the fourth man to complete the Grand Slam of World Cup, World Championships and Olympic success.
USA's Kayla Harrison clinched Judo gold in the women's Half-Heavyweight (70-78kg) category after beating Britain's Gemma Gibbons in a hard-fought final.