Team GB have won six gold medals in one day after sensational victories in athletics, rowing and cycling.
There were incredible scenes in the Olympic Stadium as Jessica Ennis won the heptathlon shortly before Greg Rutherford pulled off a shock victory in the long jump.
In front of a rapturous crowd that included the Duke and Duchess of Cambridge, Mo Farah crowned Britain's "Super Saturday" by winning the 10,000m.
With two more golds in the rowing and another in cycling, it was Britain's most successful day at the Olympics for more than 100 years.
Britain now has 29 medals in total - 14 gold, seven silver and eight bronze - and stands third in the overall medal table.
Ennis, who has been the poster girl for London 2012, went into her last event - the 800m - with a huge lead and comfortably won the race and with it the overall contest.
Women's cyclists Laura Trott, Joanna Rowsell and Dani King
Earlier, the 26-year-old from Sheffield had wowed the capacity crowd by producing 6.48m in the long jump and a lifetime best of 47.49m in the javelin.
After clinching victory, she sank to the floor and wept with joy. "I am so shocked, I can't believe it. I am so happy," she said.
Her medal glory was described as "the moment of the Games" by so many spectators and fellow athletes.
Her first coach, Mick Thompson, said: "You can't get better than this. Where does she go next?"
Katherine Copeland and Sophie Hosking struggled to absorb their rowing win
Former sports minister and ex-Sheffield MP Richard Caborn, who was in the stadium, said: "She's our golden girl. She's stuck with Sheffield and Sheffield's stuck with her."
Sir Chris Hoy said on Twitter: "That's how to do it!! Finish the job in style! Just superb @J--Ennis!!!!
Tom Daley also took to the microblogging site to say: "Absolutely amazing Jess!!! Congratulations! Moment of the games right there!!!"
And Prime Minister David Cameron tweeted: "Awe inspiring win for Jessica Ennis. Proud to be cheering her on with the home crowd. Atmosphere electric on #SuperSaturday."
Rutherford, 25, from Milton Keynes, leapt 8.31m to become the first British man to win long jump gold for nearly 50 years and secure the second athletics gold of the night.
The third was only moments away as Somali-born Farah blew away the field to take the 10,000m title. "This is the best moment of my life," he said.
Laura Robson and Andy Murray are through to the mixed doubles final
Across the Olympic Park at the velodrome, Laura Trott, Joanna Rowsell and Dani King were triumphant in the women's team pursuit and also smashed the world record.
After their crushing defeat of the US in the final, a jubilant Trott said: "It has been my dream since I was eight - and we have just gone and done it."
Team GB has now won a staggering four of the five gold medals on offer so far in the track cycling, with five events still to come.
At Eton Dorney, it was another glorious day on the water with Britain winning two more golds and narrowly losing a third to take silver.
Katherine Copeland and Sophie Hosking were completely stunned after they won the lightweight women's double sculls at Eton Dorney.
The pair became the third female British crew to take Olympic gold this year after finishing a length and a half ahead of their closest rivals China.
Fighting back the tears, Hosking said: "I can't believe this is real, that we just won. We just won the Olympics!"
Their win came after joy and heartbreak in the men's team as the coxless four won gold but the men's double scullers narrowly failed to defend their Olympic title.
Andrew Triggs Hodge, Pete Reed, Tom James and Alex Gregory led from the front to win the four, which means Britain has now won the event in the last four Olympics.
Reed said: "The hours we do, the pain - it was all worth it in the end."
But in the double sculls, Zac Purchase and Mark Hunter were beaten at the death by Denmark and were distraught at only taking silver.
There had also been disappointment earlier when Britain's Helen Jenkins failed to win a medal in the women's triathlon in Hyde Park. The reigning world champion finished fifth after struggling with injury.
Over at Wimbledon, Andy Murray and Laura Robson guaranteed at least silver by winning a tense mixed doubles semi-final against Australia.
However, the British team crashed out of the football after losing the quarter-final to South Korea on penalties.
Elsewhere, history was made when South Africa's Oscar Pistorius became the first double amputee to compete in the Olympics and Paralympics, advancing to the semi-final of the 400m.