American Gay admitted he was unhappy with his performance after winning the men's 100 meters.

Tyson Gay (L) of the U.S. wins the men's 100 metres ahead of second-placed Marlon Devonish of England during the British Grand Prix athletics at the Don Valley Stadium in Sheffield, northern England on Sunday, July 15, 2007. [Reuters]

Gay, the fastest man in the world this year with 9.84 at the U.S. Championships last month, finished in 10.13. Britain's Marlon Devonish was 0.10 behind in second place.

Persistent rain in Sheffield put paid to Gay's hopes of beating the world record of 9.77 seconds, which is jointly held by Asafa Powell and Justin Gatlin.

"I came to the track yesterday and the sun was out and it was warm, so I was expecting the same thing but the weather turned around," the 24-year-old told reporters.

"I really, really expected to run better but I'm a little rusty and my body just wasn't ready yet.

Olympic and world champion Wariner failed to race the 400 meters, losing his footing as he came out of the blocks.

American Angelo Taylor took advantage of Wariner's misfortune, winning in 45.25 seconds, 0.39 seconds ahead of Australia's John Steffensen.

South African Pistorius was disqualified for running outside of his lane after trailing in last in 47.65 on the wet track.

Liu Xiang of China, the men's 110 meters hurdles world record-holder, won his race in 13.23 seconds, 0.04 seconds ahead of American Ryan Wilson.

He is now looking forward to next month's world championships in Osaka, Japan.

"I am confident for the world championships and of course will try my best to do well in the competition," he said.

America's Wallace Spearmon won the men's 200 meters in a time of 20.08 seconds, narrowly edging out Usain Bolt of Jamaica, while Ethiopian Kenenisa Bekele enjoyed a comfortable victory in the men's 3000 meters.

Allyson Felix won the women's 200 meters, finishing 0.09 seconds ahead of fellow American Sanya Richards, posting a time of 22.35.

Felix said: "The weather wasn't the best so it was a case of getting to the line first. I have been working on my curve running so I am happy with that."

Alice Schmidt of the United States won the women's 800 meters while Britain's Nicola Sanders held off a challenge from American Monique Hennagan to win the women's 400 meters.