Usain Bolt capped his stunning rise to stardom with an Olympic title  -  without even really trying  -  by setting a world record on Saturday to win the 100 meters.

With Tyson Gay out in the semifinals, the 21-year-old Jamaican seemingly only had Asafa Powell to beat, but when he looked around and realized he was all clear with 30 meters to go, he coasted and still set a world record of 9.69 seconds.

Well behind, Richard Thompson of Trinidad and Tobago took the silver medal in 9.89, and Walter Dix of the United States was third in 9.91.

Usain Bolt of Jamaica points at his race time after winning the men's 100m final of the athletics competition in the National Stadium at the Beijing 2008 Olympic Games August 16, 2008. [Agencies]

Powell again crumbled under the pressure of a big competition and finished fifth.

If athletics was looking for a defining moment to get the sport back on track after years of doping scandals, this was it. And the sellout crowd of 91,000 at the Bird's Nest let out a huge cheer, realizing it had seen something historic under the Olympic flame.

With a third of the race to go, Bolt had the luxury to look right, realize he was in a class all his own, stretch out his arms, and pound his chest as he crossed the line, slicing 0.03 seconds off the record he set earlier this season.

Soon he settled and produced a signature move, lining up an imaginary bow and arrow and letting go of that now-famous imaginary bolt.

So confident was he that he already had done the same during the presentation for the race, too.

He looked like a wide-eyed giant, happy to take in the whole occasion ahead the race.

Afterwards, he became the happiest of Jamaicans with the biggest of grins, his canary yellow shirt disappearing in a sea of friends while reggae music blared.

What was supposed to be a three-way battle turned into a one-man show never seen before. In four races in two days, not once did he push himself to the limit, yet produced the most stunning series of races.

All for a guy who was hardly known outside his Caribbean nation at the start of the season.

Jamaica's Usain Bolt celebrates after winning the men's 100m final at the "Bird's Nest" National Stadium during the 2008 Beijing Olympic Games on August 16, 2008. [Agencies]

The tall, laidback Jamaican raised his arms in triumph well before he crossed the line, sealing a remarkable transition from 200 meter specialist to winner of the showcase race of the Olympics.

Bolt only began racing the 100m in the last year, putting his fellow sprinters in the shade with his performances. He first really showed his threat in May, when he set a world record time of 9.72 in New York.

Much of Jamaica was expected to have clustered around televisions to watch the extraordinary run and will have jumped for joy.

Despite a tradition of producing world-class sprinters, the Caribbean island had never before won a men's 100m gold at the Olympics.

Bolt can now set his sights on becoming the first man to win the 100m and 200m Olympic double since Carl Lewis in 1984. He will be full of confidence ahead of Wednesday's 200m final.

Father reveals Bolt's secret weapon

Usain Bolt streaked to 100 meters Olympic gold at the Beijing Olympics on Saturday thanks to yam power, his father said.

Wellesley Bolt said his son was partial to the vegetable grown in the north-western area of Jamaica where the sprinter was born.

"It is definitely the Trelawny yam," Bolt senior told Reuters seconds after his son smashed the world record.

Agencies