Olympic Swimming:Michael Phelps, his emotions overflowing as he swam his last competitive race before retiring, ended his record-breaking career the only way he knew how, by winning another Olympic gold medal tonight.
Joining forces with his American team mates, Phelps gave the sporting world one last view of his incredible talent and determination to win when the United States won the men's medley relay on the final day of the swimming competition at the London Games.
It was the perfect ending for the most decorated Olympian of all time who built a stockpile of medals that once seemed unimaginable. He finished his career with 18 golds, twice as many as any other Olympian in any sport.
Phelps also won two silver and two bronze medals during his career, giving him a total of 22, yet another record. Soviet gymnast Larisa Latynina held the previous record for almost half a century but Phelps set a standard that could last even longer.
The US have never been beaten in the men's medley relay at the Olympics and the outcome of Saturday's race seemed a formality when Phelps teamed up with backstroker Matt Grevers, breaststroker Brendan Hansen and freestyler Nathan Adrian.
The Americans were second at the halfway stage but the outcome was foregone conclusion when Phelps rolled his powerful shoulders over for the last time to put them back in front.
Japan finished second and Australia third but no-one could stop an American team on a mission to give Phelps the perfect send off.
The US also won the women's medley relay on Saturday to give Missy Franklin, who has emerged as the new face of the American team, her fourth gold medal in London.
Franklin teamed up with breaststroker Rebecca Soni, butterflyer Dana Vollmer and freestyler Allison Schmitt to smash the world record set by China three years ago.
Australia finished second and Japan third but neither could keep up with the Americans after Franklin gave them the lead after the opening backstroke leg.
The 17-year-old won four golds in London, the same number as Phelps, while Vollmer and Schmitt both won three and Soni two as the U.S finished the eight day swimming competition with 16 golds, the same as the rest of the world combined.
"It is unreal. That was the perfect way to end the meet," said Franklin.
China finished second with five golds after Sun Yang obliterated his own world record to win the 1500 freestyle final and become the first man in 32 years to complete the long-distance double.
Sun followed up his win in the 400 freestyle on the opening day of competition to win the gruelling 30-lap race in a time of 14 minutes 31.02 seconds, slashing more than three seconds off the previous world record of 14:34.14 he set at last year's world championships in Shanghai.
Canada's Ryan Cochrane took the silver medal while Tunisia's Oussama Mellouli, the Beijing Olympic champion, collected the bronze.
There was high drama before the start when Sun lost his balance and tumbled into the water after an official aborted the start when someone in the crowd yelled out.
Swimmers receive an automatic disqualification for false starts but Sun was allowed to compete because the official starter had already aborted the start.
"I can't even think about it. I was really worried," Sun said. "I looked at my parents at first. I don't know what they were thinking at that moment and I had to prove myself if I was given a second chance."
When the race did get away, Sun regained his composure and went straight to the lead, churning through the water with seemingly effortless ease, and brought the crowd to their feet when he sprinted the last lap looking as fresh as when he began.
Ranomi Kromowidjojo of the Netherlands completed the women's spring double by winning the 50 freestyle gold in 24.05, ahead of Aliaksandra Herasimenia of Belarus and her fellow Dutchwoman
Marleen Veldhuis.