The United States stunned France in an epic men's 4x100m freestyle relay final on Monday to keep Michael Phelps's dream of eight gold medals at the Beijing Olympics alive.

Phelps swam the lead-off leg of the relay, but it was anchor Jason Lezak who delivered the victory, mowing down France's vaunted sprinter Alain Bernard in the final meters to complete a world record-shattering swim of 3min 08.24sec.

When his veteran team-mate touched the wall, Phelps let out a scream of triumph, punching his arms in the air as teammates Garrett Weber-Gale and Cullen Jones joined him in the celebrations.

"Unbelievable! Jason finished that race way better than we could have even asked for," Phelps said. "For that last 50, I was thinking 'this is going to be one close race'.

"The last 10 to 15 metres were incredible. I lost my voice, and I was definitely pretty emotional after that."

Trailing at the final turn, Lezak relentlessy pursued Bernard, but it wasn't until the final 10 meters that the American was able to pull level and, finally, edge ahead as he touched with an astonishing split of 46.06sec.

Phelps's lead-off time of 47.51 was an American record - just one-hundredth of a second off Bernard's world mark coming into the Games.

The French ? Amaury Leveaux, Fabien Gilot, Frederick Bousquet and Bernard ? took the silver in 3:08.32.

A blistering first 50m may have been Bernard's undoing, leaving him with too little to hold off Lezak at the end.

"I knew I had to accelerate, but it got harder," Bernard said.

Adding to French disappointment, Bernard's individual 100m free world record of 47.50 was eclipsed by Australian lead-off swimmer Eamon Sullivan, who clocked 47.24 in setting Australia on course for bronze in 3:09.91.

Disappointment for SA

All three medal-winning squads ? as well as fourth-placed Italy and fifth-placed Sweden ?? were well under the world record of 3:12.23 set by the US heat swimmers on Sunday night.

South Africa, who won gold in a world record in Athens, were seventh ? their time of 3:12.66 an African record but nowhere near the medals this time around.

The relay had been touted as the biggest stumbling block to Phelps's bid for an unprecedented eight gold medals at one Games.

Just how seriously the French were taking the clash was made clear early on Monday, when Leveaux withdrew from the semifinals of the 200m freestyle in order to save himself for the relay.

The drama unfolded an hour and 13 minutes after Phelps ? who won the 400m individual medley in world record-crushing style on Sunday ? continued his quest for a second individual gold in the 200m free semis, posting a conservative fourth-fastest time overall.

Even before Phelps hit the water, the Water Cube was buzzing as Zimbabwe's Kirsty Coventry broke the women's 100m backstroke world record with a time of 58.77sec in the semifinals.

Japan's Kosuke Kitajima defended his 100m breaststroke gold from Athens with a world record time of 58.91sec.

Kitajima broke the previous record of 59.13 set by American Brendan Hansen at Irvine, California, on August 1, 2006.

Norway's Alexander Dale Oen took the silver in 59.20, four-hundredths slower than his leading semifinal time, and France's Hugues Duboscq claimed the bronze in 59.37.

Hansen was shut out of the medals, finishing fourth in his only individual event in Beijing thanks to his sensational failure to qualify for the 200m breast at the US trials.

Libby Trickett gave Australia's vaunted women's team another gold, capturing the 100m butterfly in 56.73sec.

It was Trickett's first individual Olympic gold and extended Australia's hold on the event for a third straight Games.

Christine Magnuson of the United States took silver in 57.10, with Australia's Jessicah Schipper third in 57.25.

Teenager Rebecca Adlington captured Great Britain's first-ever individual women's Olympic freestyle gold with a thrilling triumph in the women's 400m.

The 19-year-old trailed by more than a second at the final turn, but surged past American Katie Hoff on the final length to win in 4:03.22.

Hoff was second in 4:03.28, and Joanne Jackson completed a great race for Britain by taking bronze in 4:03.52.