James Lawton: Tomfoolery just a mask for Olympic champion Usain Bolt

Bolt was masterly in the nonchalant way he conquered his world

Usain Bolt – and his trademark celebration – after the 100m last night (PA)

The fastest gun in the world is still beautifully oiled, still consummately able to shoot down anyone who might doubt him.

That was the requirement of the man who made himself a wonder of the world four years ago and who last night proved that those who still held him in awe were absolutely right.

Usain Bolt, shortly before his 26th birthday, larked even more extravagantly than he did before erupting so sensationally in Beijing in the last Olympics, but again it was the tomfoolery of someone with deadly and infinitely justified intent.

Yohan Blake, the 22-year-old who so many expected to see triumph, ran a personal best — and so did Justin Gatlin. But they were simply destroyed, along with the idea that this was a vulnerable champion who did not have powers beyond the comprehension of all his rivals.

The American Tyson Gay, another left in his mighty wake, hinted as much when he said, "He's the guy who's been where we haven't."

It is a place he still occupies without any serious challenge and he knew it well enough at the finish. "There is talk and talk but it is just talk. I went out tonight and I knew I could do the business. I just went to show I could do it again – and I always believed I could."

This time he could only break his own Olympic record with a huge, loping, power-laden dash to the line in 9.63sec, 0.06 of a second faster than his last triumph and, after all the injury worries, just a stride or so away from his world-record mark of 9.58.

There was an indication earlier in the evening that he was indeed ready to once again re-establish his unique place in the history of foot racing.

It may be hard to imagine a thunderbolt rolling along like Ole Man River but this was less so when Bolt cruised into the final slightly less than two hours before the moment that had for so long been seen as the dramatic centrepiece of these Olympics.

In his first heat on Saturday he confessed to a stumble at the start and a certain difficulty in engaging the mechanics of his extraordinary running action, the long earth-consuming stride which smashed the world and Olympic record in Beijing four years ago – and then brought the mark down to a scarcely credible 9.58 in Berlin precisely a year later. There may not have been so many pyrotechnics leading to last night's last act, only defeats by his young Jamaican team-mate Blake, but the idea that he was beset by crisis was certainly put on hold when he arrived for the great showdown as third fastest qualifier – behind Gatlin and Blake.

As Dwain Chambers was forced off the stage he had fought so hard to regain – he ran 10.5 against Bolt's 9.87 in the second semi-final – the great man took a leisurely glance behind and promptly decided that he could spare himself any more serious effort.

Both Gatlin (9.82) and Blake (9.85) had looked ferociously brisk. Bolt, by quite startling comparison, appeared to be mildly exercised. If this was just another touch of psychological warfare, it was conducted with some of the usual panache. He rolled his eyes and then wagged a finger. It was if to say that that it had been such folly to doubt him, a suggestion that carried a lot more weight than it might have done 24 hours earlier.

It meant that the aura of Bolt as the fastest man on earth had at least a few more hours – or maybe eternity as the first man to retain the Olympic title if we put aside Carl Lewis's elevation after the drug bust on Ben Johnson in Seoul in 24 years ago.

The latter possibly was certainly sharply indicated by the huge movement in the betting odds after Bolt's strolling finish in his semi-final. Before going in, he was a mere 8-11. Coming out, he was a stunning 2-7. Blake, his recent conqueror, was at 7-2 while Gatlin, the fastest final qualifier by 0.3 seconds was a distant 16-1.

The men who need to be right had passed an early verdict, while Michael Johnson declared, "It is Bolt's race to lose."

Really, what the race was for was an announcement of a stunning ability to cover the ground, enforce amazing standards of achievement in the most dramatic race that the Olympics ever stage.

Bolt was masterly last night and thrilling in the ostensibly nonchalant way he re-conquered his world.

Of course he wasn't nonchalant, he wasn't playing the clown. He is about the vocation of his life. He was about the serious business of being the fastest man the world has even known.

It is title that for some time is unlikely to feel the breath of a threat.