World record holder Asafa Powell [Images] pulled up injured in the 100 metres and Olympic pole vault champion Yelena Isinbayeva became the first woman to clear five metres at a surprise-filled London [Images] Grand Prix meeting on Friday.

Watched by the greatest pole vaulter of them all, Ukrainian Sergei Bubka, Isinbayeva sailed over five metres to improve on her world record of 4.96 set on her previous attempt.

It was the 23-year-old Russian's fourth world record of the month and the 17th of her career.

She sank to her knees in disbelief after clearing the height on her first attempt.

"It was my dream to be the first woman over five metres," said Isinbayeva.

"I can't explain my feelings. I don't know how much higher I can go, maybe 5.05 or higher."

Isinbayeva's efforts earned her $50,000 and an undisclosed five-figure sum from the meeting's sponsors.

The 100 metres was billed as a showdown between the world's two fastest men, Powell and Olympic champion Justin Gatlin.

Powell powered out of the blocks but then fell to the ground after appearing to aggravate a groin injury.

American Gatlin, running in the next lane, won the race in 9.89 seconds, his fastest time this season. Leonard Scott of the US was second in 9.94 and world champion Kim Collins of St Kitts and Nevis finished third.

The world championships in Helsinki start on August 6.

"Asafa will have a scan tonight and based on that will receive treatment tomorrow," said the Jamaican sprinter's agent Paul Doyle. "The picture is not good with the worlds only two weeks away.

SLIGHT STRAIN

"The injury appears to be a slight strain high on Asafa's groin. Perhaps a slightly different injury from the groin problem troubling him earlier this week."

Gatlin said: "Knowing that the fastest man in the world was lining up with me pumped me up.

"I saw in my peripheral vision Asafa go backwards but I didn't know he was injured. That made me hesitate a little but then I just went on to win and entertain.

"The time was good and I have no problems looking forward to the world championships now, it's going to be good, if not the best," added the 23-year-old.

Powell and Gatlin had been due to clash in Rome earlier this month but the Jamaican pulled out with a groin injury.

Gatlin was given the verdict over Powell in their only previous meeting this year, in Eugene, Oregon, even though both were timed at a wind-assisted 9.84 seconds.

The 22-year-old Powell ran a world record 9.77 in the Athens Olympic stadium 10 days later on June 14.

American teenager Allyson Felix ended Olympic champion Veronica Campbell's five-year unbeaten run over 200 metres.

Felix, who finished second to the Jamaican in last year's Athens final and has not lost since, clocked 22.16 for the third fastest time in the world this year.

Campbell led on the bend but Felix, 19, came back on the home straight to overhaul her rival, whose last defeat at the distance was in March 11, 2000.

Felix's American team mate LaTasha Colander was third.

Ethiopian Kenenisa Bekele failed in his attempt to break his 5,000 metres world record but pulled away from Australian Craig Mottram on the final lap to win in 12:55.55, the sixth fastest time this year.

Britain's Tim Benjamin gave the 18,000 sellout crowd something to cheer when he overtook Olympic champion Jeremy Wariner of the US in the final 20 metres to win the 400.

Benjamin clocked a personal best of 44.75, ahead of a surprised-looking Wariner, who was second in 44.86.

American Wallace Spearmon ran 19.89, the fastest time in the world this year, to win the 200 metres.

Sanya Richards of the US beat Mexico's world champion Ana Guevara to win the women's 400 metres in 50.35.