Aussie girls take shock relay gold

Australia has taken a surprise gold medal in the women's 200-metres freestyle relay in world record time at the Beijing Olympics.

The team of Stephanie Rice, Bronte Barratt, Kylie Palmer and Linda McKenzie blew away the previous record by 5.78 seconds in a time of 7.44.31.

China finished in second 1.62 seconds behind, with defending champions the United States in third, 2.02 seconds behind the Australians.

Rice, who claimed her third gold medal of the Games, led the Australian team into second after a fantastic opening leg of 1.56.57 before Barratt took the lead in the second 200m.

But Palmer proved to be the major surprise packet with an exhilarating swim of 1.55.22 setting up a 3.14-second advantage going into the final 200m.

Anchor swimmer McKenzie hung on in the closing stages to smash the US's world record from March 2007 and win Australia's first gold medal in the event.

It also ended the Americans' unbeaten sequence of three Olympic titles in the event since Atlanta in 1996.

China took the silver medal in 7:45.93 ahead of the United States in 7:46.33.

It was 20-year-old Rice's third gold in the Beijing pool following her medley double win, with all her gold medals coming in world record time.

"It's so exciting. This is my last Olympic event here so what a great note to finish on - world record and a first place," Rice said.

"We went in knowing we had a really good chance and I wasn't nervous even though I have never led off a relay before. I was trying to enjoy the moment.

"I feel amazing, I finished such a great meet as part of the relay."

The United States broke a national record but it was nowhere near good enough to compete against the strong Aussie women's team, which now has won five gold to the United States's one.

"I did my best and ran out of room at the end and that's all I could do. It's tough but we broke the American record by four seconds so we can't complain," US anchor swimmer Katie Hoff said.

In the record splits, Rice swam 1:56.60, Barratt 1:56.58, Palmer 1:55.22 and MacKenzie 1:55.91.