It was a day that started with Olympic glory for a British swimmer whose greatest accolade will be to have a pool named after her, descended into teenage tantrums and a break-up, and ended with redemption for one of Britain's wealthiest sports stars, who fluffed his chance to make history.

The third day of competition at the Beijing Olympics was not so much sport as grand opera for Britain, with a plot that veered giddily from ecstasy to despair. It was the former for Rebecca Adlington, who stunned the swimming world, and beyond, by storming to a fingertip victory in the 400metres freestyle, just beating Katie Hoff, the world-record holder from the United States, on the way to an unexpected gold medal.

As the crowd at the Water Cube aquatic centre went wild with excitement and surprise, the 19-year-old from Mansfield clambered out of the pool and calmly announced: “I'm really disappointed with my time.”

While she took winning the first gold medal by a British woman in the pool for 48 years in her leggy stride, Adlington's family were leaping from their armchairs at home, after watching the race in the early hours of the morning. Kay and Steve Adlington had wanted to be in Beijing to watch their daughter compete in the 800metres event on Saturday, only to discover that they had lost £1,100 after buying airline tickets from an internet company. The tickets never turned up.

But they will, after all, be in their seats at the Water Cube to see if their daughter can win a second gold medal after The Times commandeered two tickets. The couple fly tomorrow, leaving behind a Nottinghamshire town which is busy planning how to celebrate its new celebrity. The first suggestion is to name the municipal pool where Adlington learnt to swim after the new Olympic champion.

Unfortunately, name-calling was the only thing to be heard after Tom Daley's much-heralded appearance as Britain's youngest Olympic competitor. With Blake Aldridge, his diving partner, Daley finished last in the ten-metre synchronised event.

Daley, 14, had been billed as the pin-up of the pool, courted by sponsors and reducing armies of admiring girls to giggles. But his team-mate was less impressed. Aldridge accused Daley of letting him down, which led Daley's father to declare their partnership over. Rob Daley said tersely: “It's not exactly team spirit to start running your partner down. If you can't take it on the chin, you shouldn't be out there and Blake's out there because of Tom. If he's got sour grapes, there's nothing we can do about it. It's easy to blame a 14-year-old.”

There was no such discontent in Hong Kong, where Britain's equestrianism team are in the bronze-medal position before the final day of three-day eventing. Mary King's performance at the age of 47 has been remarkable. Tied for fifth on Call Again Cavalier, she showed the sort of cool and calm that would have been welcome at the diving pool earlier in the day.

Andy Murray was anything but cool as he suffered a straight-sets defeat against Lu Yen-hsun, of Taiwan, who is ranked No77 in the world, in the first round of the men's singles tennis competition. Murray is still in the hunt for a medal, though, partnering Jamie, his brother, in the doubles. They beat Daniel Nestor and Frederic Niemeyer, of Canada, 4-6, 6-3, 6-4.