It was hard to know which was the most arresting sight here in the "Bird's Nest" stadium last night – that of the trackside clock registering 19.30 seconds at the conclusion of the Olympic 200 metres final, or that of the man who had stopped it there to better Michael Johnson's monumental mark of 19.32, actually heaving for breath.
Until last night Usain Bolt was a sprinter who had clearly not tested the limits of his ability. He had annexed the Olympic 100m title here, beating his own world record with a time of 9.69sec, despite starting his capering celebration 20 metres from the line. And he had reached last night's final with a series of 200-metre jogs which made it appear as if his opponents were competing against someone on a different scale, a giant who ambled home with half an eye on the big screen at the end of the stadium just to check the leeway.
On this occasion, however, the birthday boy – he turned 22 at midnight – had it in mind to give himself an early present that he would cherish forever in the event which has been the receptacle for his dearest dreams since he was a teenager. Thus, with all opposition irrelevant and a second Olympic title assured, this 6ft 5in figure of power and leverage eschewed all playfulness and show, gritted his teeth, pumped his big fists up level with his ears and – wonder of wonders – actually dipped through the line towards his rich reward. All very unfamiliar. All very magnificent.
And so the comparisons begin. Bolt is the first man to hold Olympic 100 and 200 metres titles since Carl Lewis achieved the feat at the 1984 Los Angeles Games. He is the first to hold world records at 100 and 200 metres since his fellow Jamaican Don Quarrie was joint holder of the old, hand-timed marks of 9.9sec and 19.8sec in 1976, the year he won the 200 metres in Montreal to become the first man from his country to win an Olympic track title.
In bettering the mark Johnson set at the 1996 Atlanta Olympics, Bolt has broken a record which many observers believed would stand for 30 years.
"Everything came together tonight," Bolt said. "I just blew my mind. And I blew the world's mind."
There is certainly no doubt back home in his native country that this is the finest sprinter the world has ever seen. That judgement was implicit in the comments made in the aftermath of a race which eventually saw the US pair of Shawn Crawford and Walter Dix take silver and bronze in respective times of 19.96sec and 19.98sec following the disqualifications of the men who finished second and third, Churandy Martina of the Dutch Antilles, and fellow American Wallace Spearmon, for running out of their lanes.
Asked to quantify the effect of Bolt's performances, the Jamaican team doctor Warren Blake responded passionately: "This week we have had a hurricane which has done tremendous damage in Jamaica. But when I rang to check how my family were they told me that no one was talking about the hurricane, everybody was talking about the Olympics."
Johnson had cast doubt beforehand on Bolt's ability to better his mark because he thought the Jamaican's emphasis on 100m running in the lead-up to the Games meant he would not have enough speed endurance.
But as Bolt explained afterwards, the strategy of his coach, Glenn Mills, had been to work on 400 metres running in training to add that element. The plan worked – but even Bolt himself appeared taken aback at how well. "When I was watching the replay I was looking at myself and going 'That guy's fast!' " he exclaimed.
Lounging back in his chair and playing once more to the gallery, Bolt insisted that this victory meant more to him than his 100m title. "The 200m has been my love ever since I was 15 and I was the youngest to win the world junior title. I have been dreaming of this since I was small. And I know it means a lot to the country because I have talked on the phone to our Prime Minister and he told me that Jamaicans were celebrating in the streets.
"A lot of people compare me to Michael Johnson but I don't compare myself to a lot of other people because I'm trying to be just me. Michael is a great athlete and he revolutionised the sport. I just changed it a little bit."
To those who question the legality of Bolt's alterations in the light of the dismal doping history at 100 and 200 metres in recent years, Dr Blake responded: "All our athletes have undergone extensive testing, more than enough. If we had been cheating, we would have been caught by now. It's a pity the testing has to happen but it validates all the results we have had. For years we have wondered how we would do with a level playing field, and now we know."
In the wake of Bolt's latest flourish, Johnson – the original Superman – had responded with uncharacteristic fervour. "Simply incredible," he said. "This guy is Superman II."
But this guy wasn't having any of that. "I'm Lightning Bolt," he proclaimed with a grin. And striking twice...
Men's double sprint winners
2008: Usain Bolt (Jamaica)
1984: Carl Lewis (US)
1972: Valery Borzov (USSR)
1956: Bobby Joe Morrow (US)
1936: Jesse Owens (US)
1932: Eddie Tolan (US)
1928: Percy Williams (Can)
1912: Ralph Craig (US)
1904: Archie Hahn (US)