Tyson Gay gave Usain Bolt a reminder of his pedigree when the world champion defied a groin injury to win the 200 meters at the London Grand Prix on Saturday in 20.00 seconds.

Triple Olympic champion Bolt, who won Friday's 100 in a time of 9.91, did not take part in the 200 but the pair is expected to go head to head over both sprints at next month's Berlin world championships.

Asked whether world record holder Bolt was the favorite for the 100 title in Berlin, Gay told reporters: "Of course I don't agree with that.

"He has the 100 pretty technically sound and I'm still working on it, but he knows that I am close to being the only one who can beat him."

The American is the fastest man in the world this year with a best time of 9.77.

However, Gay, who failed to make the Olympic 100 final last year after suffering an injury at the US trials, again faces the prospect of turning up for a major championships not fully fit. "I haven't trained for a couple of weeks. My groin is a bit tight on me," the 26-year-old said.

Jamaican Bolt was the major draw at the two-day meeting and he delighted the crowd again with a blistering final leg in the 4x100 relay to anchor his Racers Track Club team to victory in 37.46, the fourth fastest time ever.

On the subject of Gay, he said: "I haven't been watching Tyson Gay run and I know people are saying he's my main threat in Berlin but I don't think about any one person. I just know what I need to do."

Crystal Palace was also treated to two world-leading performances in the sunshine.

Ethiopian Tirunesh Dibaba won the women's 5,000 in 14 minutes 33.65 and American Lashinda Demus clocked 53.65 in the 400 hurdles beating Jamaican Olympic champion Melaine Walker, who was second in 54.55.

(Agencies via Shanghai Daily July 27, 2009)