All eyes are on Britain's first gold medal hope, Mark Cavendish, after the greatest show on earth opened in spectacular fashion.
The 27-year-old world champion is a hot favourite for the men's cycling road race and is expected to unleash his trademark sprint finish down The Mall in central London later.
It comes after a UK TV audience of 26.9 million people watched some of Britain's greatest Olympians team up with young athletes to light the Olympic cauldron.
Tour de France hero Bradley Wiggins, who is also cycling with Team GB in the men's road race, rang the giant bell which marked the start of the show at the Olympic Stadium in Stratford, east London.
Cavendish has already been anointed champion in many people's eyes, but surviving the Box Hill loop with a small enough deficit to allow him and his British team-mates to chase any riders up the road is integral to success.
Cavendish, who has lost nearly 9lb (4kg) to improve his climbing ability, said he will need the full support of his four team-mates, Tour winner Wiggins, Chris Froome, David Millar and Ian Stannard.
"If I didn't have a team here, there's no way I could say I'll get over Box Hill nine times alone," he said.
"It's not just Box Hill, it's everything after it. Luckily I've got four of the strongest bike riders in the world around me."
Swimmer Hannah Miley is also a genuine contender for a British medal in the 400m individual medley. The 22-year-old is strongly fancied to add to the silver medal she won at last year's World Championships in Shanghai.
And at Horse Guards Parade, Steve Grotowski and John Garcia-Thompson will make history when they become the first men to represent Great Britain at Olympic beach volleyball, taking on Canada's Martin Reader and Josh Binstock.