Gay, who was unbeaten over 100m last season, recorded his time at a low-key event in a heat in the National Training Center Sprint Series in Clermont, Florida.

Bolt, who has won his first two 100m races in 9.91sec this year following a 10-month absence recovering from a back injury, knows he has a way to go to regain his dominance.

Gay, 28, beat Bolt at the Stockholm Diamond League meeting last August, but has said he needs to improve to keep up with the triple Olympic champion.

The 2007 world champion bettered the world best of 9.89 run by Mullings in May.

The world's top two sprinters are not scheduled to go head-to-head until the World Championships in Daegu, South Korea, in August with Gay insisting that Bolt, who holds the world record 100m time of 9.58, remains the dominant athlete.

Bolt continues his Diamond League season in Oslo in Norway on June 9, while Gay next runs the 100m at the Diamond League meeting in New York on Saturday June 11.

Meanwhile high hurdler David Oliver, whose 20-finals unbeaten run was halted by China's Liu Xiang at last month's Shanghai Diamond League meeting, gained a measure of revenge in the Prefontaine Classic in Eugene as he defeated the former world and Olympic champion with a time of 12.94, the fastest in the world this year.

Liu, trying to regain his 110m hurdles dominance after an Achilles injury battle, which scuppered his 2008 Beijing Olympics bid, led Oliver to the first hurdle by the barest of margins.

But the big American had powered past by the third, en route to a blistering early-season time.

"I'm just happy for a good performance," said Oliver, adding that he knew from the opening strides that he was in a good rhythm.

"I took care of business at the start - like I didn't do in Shanghai."

And in another exceptional sprint performance, American Carmelita Jeter won the women's 100m in a world-leading time of 10.70.


Mullings (pictured in green) had come into the meet with a world-leading 9.89 to his credit, set last month at a low-key event in Clermont, Florida – only to learn that Gay, his US training partner, had bettered it earlier in the day at the same venue.

Mullings credited Gay with helping him define his focus and improve his times this year.

"I just figured out how to do it," he said.

"The last couple of years, I always rushed my first third. Now I'm more patient."

Mullings admitted that he was exhausted after flying in from Europe just days before.

American Michael Rodgers was second in 9.85 and fellow Jamaican Nesta Carter third in 9.92.

Former Olympic and world champion Justin Gatlin, returning to the meeting after serving a four-year doping ban, finished sixth in 9.97.

Gatlin said his sights remained firmly on booking a World Championships berth at the US trials later this month.

Caster Semenya, whose 800m victory at the 2009 World Championships in Berlin was followed by a gender controversy, finished second in the women's 800m, but said she was not disappointed.

She closed from eighth to second on the final lap, but left herself too much to do and couldn't threaten race winner Kenia Sinclaire of Kenya, who won in a world-leading time of 1min 58.29sec.

"The time is good, under two minutes, 1:58," said Semenya, who was runner-up in 1:58.88.

Britain's Greg Rutherford missed setting a British record in the long jump – by 0.1metres per second.

The former European silver medallist's winning effort of 8.32 metres was two centimetres further than he had achieved at the World Championships in Berlin, but a following wind marginally over the allowable limit of two metres per second annulled his effort for record purposes, although he did win the event.

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