London Olympics poster boy Tom Daley missed out on a medal on in the men's synchronised 10-metre platform, as Chinese favourites Cao Yuan and Zhang Yanquan won gold.
Daley and partner Pete Waterfield had held a slender lead at the half-way point and were in with a chance of clinching Britain's first gold at the Games, but fluffed the fourth dive, winding up just out of the medals.
"It (fourth) is the worst place to finish in the Olympics," said Waterfield. "I'd rather finish last, at least then you've missed every dive," he said.
Teenager Daley, whose appearance at the Aquatic Centre was greeted by the sort of roar of approval from the audience that is more often associated with pop stars, was more stoic.
"Being so close to a medal is tough but that's sport for you and that's going to give us more motivation for the individual event" - Tom Daley
Both will take part in the individual 10-metres platform event on Aug. 10.
Watched by British Prime Minister David Cameron and Britain's Prince Harry, the British pair received the highest marks they had ever managed for the first two compulsory dives, but lost vital marks on their reverse 3-1/2 tuck when Waterfield over-rotated.
Daley is a household name in Britain after he competed at the Olympics in Beijing aged 14 before going on to win the individual world title for the 10-metre platform in Rome at the age of 15.
But his early fame has raised questions as to his ability to juggle his celebrity status with the demands of training.
His Russian performance director caused a stir before a test event in February when he said Daley was in danger of failing to achieve his potential and becoming the sport's answer to former tennis glamour girl Anna Kournikova.
Teenagers Cao and Zhang were diving at their first Olympics and were considered the weakest link in China's bid to get a clean sweep of eight diving golds in London. Their victory with 486.78 points, on Monday makes that ambition look more likely.
"It's almost like China versus the world," said David Boudia, who took the bronze with partner Nicholas McCrory on 463.47 points, a day after their compatriots claimed the first diving medal the U.S. has won since 2000 in the women's synchronised three-metre springboard.
Cao and Zhang clinched the title with well-chosen dives that did not score as high on difficulty as some other teams' choices but were almost flawlessly executed.
Cao dismissed comments Daley had made in the past that the Chinese athletes could crack under the pressure of expectation.
"Only Tom thinks that," said cherub-faced Cao.
"I've never felt like that. I don't look at other athletes, I don't feel any pressure."
Ivan Garcia Navarro and German Sanchez Sanchez won Mexico's first medal at London with a high-risk tactic, gambling on two dives with the highest rated difficulty in the contest that were less polished but ensured they accumulated enough points to finish on 468.90 and with the silver.