Latest swimming results

Aaron Peirsol set a new world record on the opening backstroke leg of 53.45 seconds to fire the US into a dominant lead which they never relinquished.

The result means a watching Michael Phelps claimed a record-equalling eighth Olympic medal at one Games.

Germany took silver with Japan third while Great Britain finished eighth.

The British quartet of Gregor Tait, James Gibson, James Hickman and Matt Kidd trailed last in 3:37.77.

"We lifted the level for the British trials so high, maybe we were in better Olympic shape earlier in the year," said Hickman.

It's such a special way to end a meet US swimmer Aaron Peirsol

"We've had vast improvement over the last three years and improving again was a little bit too much."

The US team of Peirsol, Brendan Hansen, Ian Crocker and Jason Lezak bettered their own mark to take gold in 3:30.68.

"It's such a special way to end a meet," said Piersol, who had already clinched the 100m and 200m backstroke titles in Athens.

Phelps handed his place in the relay to Crocker but watched his team-mates earn him another medal.

As the 19-year-old raced in the heats he picked up his eighth medal at a single Olympics equalling Russian gymnast Alexsander Dityatin's feat in 1980.

Phelps won individual 200m and 400m medleys, 100m and 200m butterfly crowns and as part of the men's 4 x 200m freestyle.