They had wondered if he was ready, rumours of injury, speculation over his commitment to training, his wavering form. But when that gun went in the Olympic Stadium, Usain Bolt delivered a weighty blow to anyone who had doubted or questioned, or thought they might beat him.

An Olympic 100m record of 9.63sec. The 25-year-old Jamaican had to work for it but he was always ahead and the result was never in danger of being anything else. Yohan Blake, the world champion, took silver, equalling his personal best of 9.75, with Justin Gatlin third in 9.79 displaying a miraculous return to the sport following his ban. At the finish Asafa Powell, the former world record holder who has never won a global title, looked inconsolable.

Ahead of the final, on the warmup track, Blake and Bolt joked together as though back on the training ground at their Kingston track. Bolt toyed with the camera that spied on them leaping left and right, in and out of vision, with seemingly boundless energy as though he had forgotten he was about to attempt to defend the first of his Olympic titles. So the story goes he had been the same ahead of the Beijing final, rolling around play-fighting with his agent on the floor. Fine-tuning their blocks, the three Jamaicans took time out to embrace one another.

In the semi-finals all of the lead contenders turned on the speed, with Gatlin qualifying for the final in the fastest time. The American reflected the traditional stance of sprinting machismo: angry on the line, intense, he saluted the crowd, then blew himself out of the blocks to finish in 9.82. His reaction was pure aggression, clenched fists, energy and bumping chests, while Powell – comprehensively beaten into third place behind Churandy Martina – wandered away biting his lip.

Next up came Bolt, the mystery man who had kept everyone guessing as to his form. Crossing the line in 9.87, wagging his finger at the doubters, he responded to the world's questions. Like a knife through butter, his run was easy, languid, meeting little resistance. Of all the semi-finalists, he looked the most comfortable. Britain's Dwain Chambers tried to keep pace with him up to 40m but when the Jamaican accelerated no one could get anywhere near him. His burst of speed gave such momentum that almost as soon as he was ahead he seemed to slow down again, glancing right and left, before leisurely crossing the line.

Blake's performance nestled between his two forerunners. Relaxed, but retaining a tension that Bolt had not shown, Blake won his semi-final in 9.85, the second-fastest qualifier. In third place Britain's 18-year-old Adam Gemili finished in 10.06, 0.01 outside his lifetime best and 0.02 off making the final as one of the fastest losers.

- www.guardian.co.uk