Usain Bolt of Jamaica sprints out of the starting blocks at the start of his men's 100 metres heats at the IAAF World Championships in Daegu
Usain Bolt of Jamaica sprints out of the starting blocks at the start of his men's 100 metres heats at the IAAF World Championships in Daegu August 27, 2011. Reuters

Usain Bolt signaled that reports of his vulnerability might be exaggerated when he stormed to the quickest time in the first round of the 100 metres heats at the world championships on Saturday.

The double world and Olympic sprint champion served up by far the most dominant victory in a time of 10.10 seconds while clearly easing up over the last 10 meters.

After a season less dominant than the previous three, some former champions and absent rivals have been suggesting that Bolt might actually be beatable in the blue-riband sprint in Daegu.

The world record holder has admitted he is not in tip-top condition but if that has dented his confidence Bolt was not showing it as he gave a vintage display of finger shooting and hair preening before the start.

Getting out of his blocks in a slick 0.153 seconds, the Jamaican was well clear of the field halfway down Daegu's blue track and gently put on the brakes as he approached the finish line.

I feel great, the 25-year-old told reporters. My goal is to go out there and execute, I came out and I did what I wanted to. I got my great start and I'm happy with that.

Bolt brushed aside talk of his vulnerability.

They are going to always say whatever they want, Bolt added. I am focused on what I want, my focus is to go out there and win and show the world I am still the best.

Bolt's quest to retain the title he won in a world record time two years ago in Berlin has been eased by the absence through injury of his most likely challengers, American Tyson Gay and fellow Jamaican Asafa Powell.

Jamaican Steve Mullings and American Mike Rodgers, two other sprinters who have run better times than Bolt this year, missed the championships because of doping violations.

The other pretenders to his sprint crown all managed to get through to the semi-finals but Bolt is clear in his own mind that he remains the world's best sprinter.

Of course, nobody has beaten me all season and nobody has broken my world record, he said.

Bolt's 21-year-old training partner Yohan Blake, tipped by former world record holder Maurice Greene as the man who could take the title in Sunday's final, ran the second fastest time to win his heat in 10.12.

Trinidad and Tobago's Richard Thompson (10.34), who has run the fifth fastest time this year of 9.55 seconds and finished second behind Bolt at the Beijing Olympics, came through in third place in heat one behind the evergreen Kim Collins (10.13).

Two other Jamaicans, Michael Frater and Nesta Carter, both won their heats in 10.26, while Zimbabwe's in form Ngonidzashe Makusha also progressed (10.31).

Olympic bronze medalist Walter Dix was the quickest of the three Americans to progress in 10.25. The semi-finals and finals both take place on Sunday evening.