After having to settle for silver at the last two Games, USA's Allyson Felix finally got her hands on an Olympic gold medal with a brilliant run in the 200m final.
Felix, runner-up at Athens 2004 and Beijing 2008 to Jamaica's Veronica Campbell-Brown, overcame a sluggish start to lead coming off the bend and was never going to be caught, the 26-year-old clocking a time of 21.88 to finish 0.21 seconds ahead of 100m champion Shelly-Ann Fraser-Pryce.
USA's Carmelita Jeter, silver medallist over 100m, took bronze with Campbell-Brown fourth and failing in her bid to become the first woman to win a track event for three Games in succession.
The USA then enjoyed a one-two in the 110m Hurdles as Aries Merritt stormed to victory in 12.92, the fastest time in the world this year and just 0.01 seconds off the Olympic record set by Liu Xiang at Athens 2004.
Team-mate Jason Richardson took silver in 13.04 with Jamaica's Hansle Parchment taking bronze in a new national record of 13.12.
World record holder Dayron Robles of Cuba pulled up injured midway through the race.
And a glorious night for the USA was completed when Brittney Reese won gold in the women's Long Jump.
Russia's Natalya Antyukh won the 400m Hurdles, the 31-year-old just holding off USA's Lashinda Demus at the finish.
Antyukh recorded a personal best of 52.70 to finish just 0.06 outside the Olympic record held by 2008 champion Melaine Walker, with Demus setting a season's best of 52.77.
Czech Zuzana Hejnova claimed the bronze medal just ahead of Jamaica's Kaliese Spencer.
Usain Bolt edged ever nearer the legendary status he craves after easing into the 200m final.
While many would already consider the Jamaican superstar a legend for winning triple gold at Beijing 2008 and defending his 100m title here on Sunday, Bolt himself insists he also has to retain his 200m title.
And the 25-year-old looks increasingly likely to do just that, effectively winning his semi-final before halfway and almost jogging down the home straight to win in 20.18.
Team-mate Yohan Blake was the fastest qualifier after also slowing down markedly in winning the opening semi-final in 20.01, but Bolt has no doubts he will put his training partner in his place once again on Thursday.
'No doubt whatsoever,' Bolt said. 'I'm ready, this is my favourite event, so I'm looking forward to it.'
Australia's Nathan Outteridge and Iain Jensen won their country's fifth gold medal of London 2012 by completing victory in the Sailing 49er class.
The pair's success was a formality and they eased home with a fourth-place finish in the medal race at Weymouth and Portland.
New Zealand's Peter Burling and Blair Tuke were assured of silver but Denmark's Allan Norregaard and Peter Lang produced a late burst to secure bronze ahead of final race winners Austria and fellow hopefuls Great Britain.
Four gold medals were handed out at Eton Dorney as the first of the Canoe Sprint finals took place.
Norway's Eirik Veras Larsen triumphed in the men's Kayak Single (K1) 1000m, finishing ahead of world champion Adam van Koeverden of Canada and Max Hoff from Germany.
Another German, Sebastian Brendel, took the men's Canoe Single (C1) 1000m title with David Cal Figueroa of Spain second and Canada's Mark Oldershaw third.
In the men's Kayak Double (K2) 1000m, Hungary's Rudolf Dombi and Roland Kokeny won gold, just ahead of Portugal's Fernando Pimenta and Emanuel Silva. Martin Hollstein and Andreas Ihle from Germany won bronze.
The Hungarian team won the women's Kayak Four (K4) 500m with Germany and Belarus also earning podium positions.
Switzerland's Steve Guerdat won the Individual Jumping Equestrian gold medal at Greenwich Park.
Six riders carried zero faults into the final individual round but only Guerdat was able to go clear.
Gerco Schroder of the Netherlands beat Ireland's Cian O'Connor in a jump-off for silver and bronze.
China completed a clean sweep of the Table Tennis gold medals for the second successive Olympics with victory in the men's Team event at ExCeL.
The team of Ma Long, Zhang Jike and Wang Hao proved too strong for the Republic of Korea, easing into an unassailable 3-0 lead. Ma and Zhang were both convincing in the Singles before Zhang combined with Wang to wrap up the job in the Doubles.
Germany beat Hong Kong 3-1 to claim the bronze medal.
The Nethelrands will meet Argentina in the women's Hockey final after they both won. The Dutch beat New Zealand on a penalty shoot-out while the South Americans ousted Great Britain 2-1.
Kaori Icho beat Jing Ruixue to claim her third successive Olympic gold and complete a clean sweep for Japan on the first night of women's Wrestling at London 2012.
Icho became the only woman wrestler to triumph in Athens, Beijing and London after she beat her Chinese opponent to record a straightforward 3-0, 2-0 win in the 63kg category final at the ExCeL.
Icho's victory came barely an hour after Hitomi Obara came from behind to register a hard-fought win over Azerbaijan's Mariya Stadnyk in the 48kg category.
Misty May-Treanor and Kerri Walsh of the United States secured gold in the all-American final of the women's Beach Volleyball at Horse Guards Parade.
The duo claimed their third consecutive Olympic title after they defeated number six seeds Jennifer Kessy and April Ross in straight sets.
China's Wu Jingyu successfully defended her -49kg Olympic title with victory over Spaniard Brigitte Yague Enrique on the first night of Taekwondo at ExCeL.
Thailand's Chanatip Sonkham and Lucija Zaninovic of Croatia claimed bronze.
In the last bout of the night, Spain's Joel Gonzalez Bonilla claimed gold as he beat Republic of Korea's Lee Daehoon in the final of the men's -58kg.
Bronze went to Russian Alexey Denisenko and Colombian 19-year-old Oscar Munoz Oveido.