London: Asafa Powell, the fastest man in the world this year, withdrew from the London Diamond League meeting just hours before he was due to run in the 100 metres at Crystal Palace on Friday.
The Jamaican said he could not afford to risk a troublesome groin injury ahead of the World Championships in Daegu, South Korea, later this month.
"I`ve had some tightness in my groin since (competing in) Budapest last weekend," 28-year-old Powell said.
"I had hoped that it would have cleared by now but it`s still there. I`ve been seeking treatment but had to make the decision today (Friday) to withdraw.”
"I am focusing on Daegu and as much as I`d like to run tonight, I just can`t take the risk with the major championships three weeks away," added Powell, yet to win a major sprint gold medal.
On the track, Kenyan 800m world record holder David Rudisha marked his British debut by setting a new UK all-comers` record of 1min 42.91 seconds.
Rudisha took over from the pacemaker at the bell and held off Abubaker Kaki to extend his unbeaten run to 30 races, beating Steve Cram`s previous record of 1min 43.22secs which was set back in 1986.
"I was feeling in great shape, I knew I was going to break this record and run 1:42," Rudisha said.
"I tried to control the race all the way. The world championships is my major target this year."
In the women`s 400m hurdles, Jamaica`s Kaliese Spencer clocked the fastest time in two years and 10th best of all time when she stormed to victory in 52.79sec, finishing ahead of compatriot and Olympic and world champion Melaine Walker.
"I`m in great shape. I wanted a personal best. There`s three more weeks before the world championships and I am hopeful of putting in a faster time," said Spencer.
"I will be focussing on the win and if the time comes with it, then great."
Walker clocked 53.90sec with Britain`s Perri Shakes-Drayton claiming third in 54.62sec.