Unsurprisingly, it was Britain's rowers who came through for the host nation.
Helen Glover and Heather Stanning lived up to expectations to win Britain's first gold of their home Olympics in the women's pair at Dorney Lake, coming through after several other British favourites had faltered at the games.
With Britain's two princes, William and Harry, watching on among a jubilant crowd, Glover wept on the podium as the gold medal was placed around her neck. A grinning Stanning looked around, taking in the cheers and the size of their achievement.
"We realized people were waiting for that," Glover said.
Britain had been growing increasingly frustrated.
Big gold-medal hope Mark Cavendish flopped in the men's road race, fellow cyclist Lizzie Armitstead had had to settle for a silver in the women's equivalent and diving poster boy Tom Daley narrowly missed making the podium after a big blunder.
Glover and Stanning, unbeaten in 2012 and rowing in Wednesday's first gold-medal event, had the weight of a nervous nation on their shoulders.
"We were mildly aware of the expectations," Glover said. "We were kidding ourselves that it wasn't happening. But as soon as we crossed the line, we realized there was a lot of expectation on us.
Rowing has long been one of the country's best sports at the Olympics, with Britain winning a gold medal at every summer games since 1984. Glover and Stanning ensured that run continued at London 2012.
They established a huge early lead under grey, threatening skies — as much as five seconds by the 1,500-meter mark — and then held on grimly as they tired late on to win by a length from fast-finishing Australia. World champion New Zealand took the bronze in what was the first of 14 rowing finals across the next four days.
"I want to say how delighted I am about Helen and Heather's gold medal in the rowing — an absolutely fantastic effort," British Prime Minister David Cameron said.
Not only did the triumph end Britain's wait for gold after four barren days of Olympic action, Glover and Stanning also became the first women to win rowing gold for Britain after decades of dominance by its men's crews.
"I want to collapse, I'm so overjoyed," said Stanning, who is an officer in the British army. She paid tribute to the country's soldiers in Afghanistan.
After crossing the line, Stanning leaned back into the lap of Glover and punched the air. They then cupped their mouths in disbelief. The two had only been spares for the country's eight boat just two years ago.
"If I can do it, take the chance," said Glover, who only took up rowing five years ago after seeing an advertisement in a paper seeking "Sporting Giants" to help the British Olympic team ahead of the London Games. "In not just rowing, but anything."
Before receiving their medals, they raised their arms together and jigged on the spot with beaming smiles. Then came Glover's tears.
To the right of them was an applauding Australian crew of Sarah Tait and Kate Hornsey.
They had been fourth after 500 metres but produced a stunning late burst to snatch silver, bettering the bronze they won at last year's world championship. Tait and Hornsey covered the last 500 metres four seconds quicker than the Britons. Another 100 metres and the host nation could still be waiting for that gold.
"My daughter was the first person I saw coming out of the water," Tait said. "It's amazing that you look up into the stands and the first person you see is a 2-year-old."
The United States was only 0.2 seconds behind New Zealand at the line in fourth.
The victory of Glover and Stanning could begin an unprecedented medal rush for the host nation at Dorney Lake.
Two more golds could come from the women's double sculls (Katherine Grainger and Anna Watkins) and the lightweight women's double sculls (Sophie Hosking and Kat Copeland). The men's crews are good bets for at least four more.
"I really hope it has a snowball effect in the coming weeks," Glover said. "In the coming days, I hope we have some great results to come from British Rowing."