London:Against a strong headwind, Usain Bolt eased to victory in the 100 meters at the London Grand Prix on Friday in his last race over the distance before the world championships next month.
The Olympic champion and world record-holder clocked 9.91 seconds at Crystal Palace.
Another of the sport's biggest stars, Yelena Isinbayeva, was stunned in the pole vault, losing for the first time in six years.
Anna Rogowska of Poland beat her on countback. Isinbayeva entered the competition at 4.68 meters, but cleared it only on her final attempt. The Russian failed three times at 4.78.
"I'm a little disappointed, it's unusual for me as I don't know how to come second," said Isinbayeva, who last lost a major event in 2003. "I had a really good indoor season and I was hoping to carry that to outdoors, but I have had some injuries which did not help with my training.
"I am confident for the worlds because I have three weeks before my competition. I will take a rest. I will be in my best shape."
Bolt was also in high spirits for the worlds in Berlin from August 15-23 after running against a 1.7 meter per second headwind.
Fellow Jamaican Yohan Blake was second in 10.11 and former world record-holder Asafa Powell, who was unbeaten on his three previous visits, finished back in sixth.
"I feel really good about going to Berlin and I'm going there on a mission," Bolt said. "I'm just glad I got through the race injury free.
"My start wasn't the best but I'm improving and I now have more work to do. I'm in really good shape right now and I don't see any reason to run myself out. I did well and was proud of myself. I got it right so I'm happy."
Bolt is confident of being in top form for the worlds. "I'm still at 85 per cent (fitness) and after this it's all training, I've got two or three weeks of good training to put in," he said. "So I guess I will be 100 per cent by Berlin."
The 22-year-old Bolt will be back on the track on on Saturday to race in the 4x100 relay. His victory returned the focus of Jamaican athletics back to the track after news emerged yesterday that five athletes from the island - four men and one woman - tested positive for banned substances. There was no suggestion that Bolt, Blake or Powell were implicated.
"As long as I'm clean I'm just going forward," Bolt said. "It's sad for the sport because the sport was getting on so well, I was trying to bring it back. This is probably a step backwards because people start questioning everybody, especially from Jamaica.
"For me it doesn't matter because I will be going out there, day after day, doing my best. I get tested all the time. It shows that people get tested and they get caught if they are on drugs."
Also on the first day of the south London meet, Debbie Ferguson-McKenzie of the Bahamas won the women's 200 in 23.11. Marshevet Hooker of the United States withstood a late surge from Emily Freeman to finish second in 23.30.
Dayron Robles of Cuba won the 110 hurdles in 13.29. Ryan Brathwaite of Barbados was second in 13.31 and Andy Turner of Britain was third in 13.31.
Mo Farah failed to break the 27-year-old British record in the 5,000, but won in 13 minutes, 9.14 seconds.
Brandon Roulhac of the United States won the triple jump with a leap of 17.33 with David Giralt of Cuba second with 17.18.
Nicola Sanders of Britain continued her return to action following a lengthy injury layoff by winning the 400 in 51.54, just holding off American pair Shana Cox and Monica Hargrove. "The wind down the home straight was pretty fierce," Sanders said.
Christian Cantwell won the shot put with a throw of 21.82, and American teammate Reese Hoffa was second at 21.55. Olympic champion Thomas Majewski was third at 21.43.