Only the 25-year-old, 6 feet 5 inch giant, has ever run faster with his World record 9.58 at the 2009 World Championships, as he dominated the race from just before the halfway mark to throttle the threats of his opponents, in particular fellow Jamaican Yohan Blake.

Bolt lowering the Olympic and then World record of 9.69 he posted in Beijing four years ago, silenced last year's World champion's gold ambitions who had to settle for matching his lifetime best of 9.75 with the USA's Justin Gatlin the 2004 Games gold medallist finishing third in his fastest ever time of 9.79.

The World record holder having raised a finger to his lips before the start to silence the noise of the highly expectant 80,000 capacity crowd and crossing himself looking up to the sky, then proceeded to produce the second fastest dash ever witnessed down the home stretch of London's Olympic stadium.

Opening a clear gap from Blake and a pursuing pack of six other sprint aces after only 40m, he forged into a clear lead and gritting his teeth proceeded to go even quicker in the final 10 metres.

Unlike at the last Games in China where he shut himself down in the final 20m, on this occasion he wasn't far enough ahead to enjoy the luxury and ran through the line as quickly as he could.

"I was slightly worried about my start," said Bolt recalling the race. "I slipped a little in the blocks. I don't have the best reactions, but I secured it and that's the key.

"My coach (Glen Mills) told me to stop worrying about the start and concentrate on the end because that's my best."

The first sprinter to defend a 100m title since Carl Lewis in 1988, relishing the atmosphere generated by the excited spectators, added: "It was wonderful. I knew it was going to be like this. There wasn't a doubt in my mind it was going to be like this."

Bolt praising his colleague Blake, admitted: "He works harder than me, but I knew what I needed to do and I have great talent. He will do better next time because he was a little bit stressed this time."

In his slipstream Blake his training partner and fancied by many to end Bolt's supremacy, found himself in a struggle to fend off Gatlin, the first of the three USA sprinters to finish who all enjoy an arch rivalry with their Caribbean rivals.

Blake known as "the beast" because of his dedication to training even on a Christmas Day and confident he could win gold, conceded "He is the fastest man in the world and I've got a silver medal. What more can I ask for? To be the second is an honour."

Gatlin was followed home by team-mate and the World's second fastest ever man Tyson Gay who after only returning to competition in June after a year's absence following a hip injury requiring an operation, was a magnificent fourth in 9.80.

Gay who ran 9.69 in Shanghai three years ago but finding the challenge on this occasion a bridge to far, said: "I really tried to do it for my family, man, but I came off short."

Then came another American Ryan Bailey who again equalled the personal best of 9.88 he achieved when leading the heat qualifiers with Churandy Martina now running for the Netherland's and Trinidad's Richard Thompson the 2008 runner up, who both also dipped under 10sec with clockings of 9.94 and 9.98.

The eighth finalist former World record holder Asafa Powell fifth for Jamaica at the last two Games would almost certainly have done so as well. But his hopes vanished 25m from the line when his hamstring, always a problem in recent years, clearly snapped although he did manage to cross the line.

David Martin for the IAAF

Bolt who a year after that lightning performance lowered his time to 9.58 when winning the World Championships gold medal, took control of his semi-final after 40m and despite easing down considerably in the final 30m still rocketed with a +1.0m's wind to a time of 9.87.

The Jamaican's pick-up out of the blocks saw him effortlessly defeat Ryan Bailey who had sped to a very impressive mark of 9.88 when equalling his two-year-old personal best in the first round but the American nevertheless still recorded a solid 9.96.

Trinidad's Richard Thompson, the silver medallist at the 2008 Games, chasing hard behind the duo clocked 10.02 which guaranteed him a fastest loser's slot in the final.

In the opening qualifier 2004 champion Justin Gatlin motored with the assistance of a +0.70 wind to a really impressive 9.82 as he was chased across the line by former Dutch Antilles sprinter - the country is now dissolved - Churandy Martina.

Martina, who lost the 200m silver medal at the Beijing Games behind Bolt when running out of his lane and now running in the colours of the Netherlands posted a national record and a new personal best of 9.91. Former World record holder Asafa Powell, a two-time fifth placed Olympic finisher, despite a very good start was left in the slipstream of the pair but the Jamaican made the final with a very respectable mark of 9.94.

The final semi saw World champion Yohan Blake and former World title holder Tyson Gay backed up by a wind of +1.7 dominated the race although Great Britain's Adam Gemili last month's World Junior champion chased them every inch of the straightway. Jamaican Blake got the verdict by 0.05sec in 9.85 but with him and his American rival eyeballing each other when slowing around 15m from the line, both indicated they plan going much faster in the final. Gemili clocked a solid 10.06 but did not progress to the final later tonight.

David Martin for IAAF

Gatlin thrilled the huge, ecstatic crowd when recovering from being last out of his blocks (reaction 0.200), he rocketed to the first ever sub-10 clocking in any Olympic first round heat with a performance of 9.97 and a following wind of +0.7m/s.

"It was good, the track was superfast and it was another good day at the office," said the 2004 gold medallist. I worked on my technique - I just wanted to go out there and give the spectators a good show."

"You feel the magic out there," said Gatlin about the fantastic atmosphere created by the packed stadium which had been eagerly awaiting the 100m heats

Then Bailey at 23-years-old, seven years Gatlin’s junior and a surprise third in the sudden-death USA Olympic trials went even faster. Aided by a +1.5m/s wind the new boy on the block who had showed his form when second at the London Samsung Diamond League, equalled his two-year-old fastest ever time of 9.88.

"I equalled my personal best," said Bailey who missed the 2011 season through injury. "I just wanted to get out and run my heat. I knew if I stayed healthy I'd be OK. It was surprisingly easy."

Just prior to that duo's historic achievements in the first heat, 2007 World 100m and 200m champion Tyson Gay, the third American contender, produced an easy looking 10.08 to beat Trinidad's Beijing silver medallist Richard Thompson by 0.06sec in 10.08.

The Jamaican response came quickly. Although Bolt, Blake and Asafa Powell didn’t dip under the 10sec marker, they all looked comfortable when moving into tomorrow's semi-finals.

Bolt was first on stage and with much less showboating than he has displayed since becoming the World's fastest man, he reined himself in 20 metres from the finish line to produce an easy looking time of 10.09.

"I expected it," said Bolt. "I'm running well, I'm happy, training is great. Reaction was good," although not enjoying the best of starts. "I made a bad step. I stumbled a bit. I'm glad it happened now."

The defending champion was followed onto the track by Powell, who preceded him as World record holder, but still has a question mark against his ability to carry his best form into major championships despite twice taking World championship bronze medals.

Powell also ran well within in his ability, cruising down the straightway to win in 10.04, with as Britain's Adam Gemili, the winner of last month's World Junior Championships, chased him home in 10.11.

Then came Blake, the reigning World 100m champion, who without really changing up any gears ran a very easy looking even mark of 10.00, which dragged Japan's Ryoto Yamagata to a personal best 10.07.

The final heat saw a host nation victory from Dwain Chambers. The fourth placer finisher at the 2000 Sydney Games set a season's best of 10.02, as did French runner up Jimmy Vicaut in 10.11. Behind them the highly rated training partner of Gay, Trinidad's Keston Bledman ran a comfortable 10.13.

David Martin for IAAF

The concept successfully introduced by the IAAF at last year's World Championships enables those countries who have no athletes with Olympic qualifying standards in any event to enter them (one man; one woman) in this innovative 100m round, giving them the opportunity to qualify for the first of the main 3 rounds.

Kobeane of Burkina Faso a landlocked west African nation, won the final qualifier in a season's best 10.42 where the first two in the four heats and next two fastest athletes progress into the main competition. The next equal fastest were Berenger Aymard Bosse and Jurgen Themen from the Central African Republic and Surinam who took their respective races both in a time of 10.55, with Artur Bruno Rojas of Bolivia winning the first contest in 10.62.

One national record - recorded by Azneem Ahmed of the Maldives who qualified as one of the fastest losers when third in his race clocking 10.79 - eight personal bests and five season's fastest times were recorded by the competitors.

David Martin for IAAF