Phelps, Garrett Weber-Gale, Cullen Jones and Jason Lezak overcame a vaunted French quartet with anchor Lezak surging past top French sprinter Alain Bernard in the final 10 meters to secure the victory.

The triumph was one that Phelps had to have if he is to beat the Olympic standard of seven gold medals at one Games established by swimmer Mark Spitz in 1972.

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

Australian sprint ace Eamon Sullivan smashed the world record in the lead-off swim in the epic men's 4x100 metre freestyle relay which kept alive American Michael Phelps's eight gold medal dream at the Beijing Olympics on Monday.

Sullivan's 47.24 seconds swim off the blocks stripped the 47.50sec world record off French rival Alain Bernard, which he had held since the European championships in Eindhoven last March.

The Australian now holds both the 50m and 100m freestyle world records and is now the favourite for both sprint events later this week at the Water Cube.

"I felt good in the warm-up. It was a fairly easy swim, there wasn't much pain involved," Sullivan said.

"With all the splits that have been done, by no means are the next few days going to be any easier."

Sullivan, 22, had already been tagged the world's fastest swimmer after breaking the 50m record three times this year.

"I have a lot of work to do, I have to find some more areas to work on and push the bar up higher," he said.

But Sullivan's achievement was overshadowed by the Americans' adrenline-charged freestyle relay victory to keep Phelps on track to becoming the greatest gold medal winner at a single Olympics.

Although Phelps swam an American record lead-off leg, it was experienced anchor Jason Lezak who delivered the victory, mowing down France's vaunted sprinter Bernard in the final metres to complete a world record swim of 3min 08.24sec.

The French took the silver in 3:08.32 and Australia claimed bronze in 3:09.91.

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

The medallists as well as fourth-place Italy (3:11.48) and fifth-place Sweden (3:11.92) were under the world record of 3:12.23 set by the United States in the heats on Sunday night.