Australia's men have taken advantage of the disqualification of the crack United States team to win the 4x100m medley relay at the world titles.

The team of Matt Welsh, Brenton Rickard, Andrew Lauterstein and Eamon Sullivan won in a time of three minutes 34.93seconds ahead of Japan (3:35.16) and Russia (3:35.51).

Sullivan produced an inspired last leg to overpower Japan's Danisuke Hosokawa for the victory.

It was the men's first gold medal in the last event of the meet, mirroring their performance at last year's Commonwealth Games.

The US were the hottest of favourites but missed the final after Ian Crocker broke during Sunday morning's heats.

It was Australia's ninth gold medal of the week.

"We just put in all on the line tonight and really had a red hot go and it was a fitting end to a great week for all of us," said Rickard.

"I turned around and saw that we were second at the 200 so I knew with (Lauterstein and Sullivan) left we were right in there with a chance of winning it."

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