Jamaican Usain Bolt blitzed to victory in the men's 100 metres Olympic sprint on Sunday, banishing doubts that he was still the fastest man on Earth.
A packed crowd of 80,000 at the main stadium roared the runners home as Bolt comfortably eclipsed training partner and compatriot Yohan Blake, who many considered his main rival going into the race.
The towering athlete broke the tape in 9.63 seconds, an Olympic record and the second fastest time ever behind his own world record of 9.58.
There were more cheers as he pointed to the sky in his trademark "lightning bolt" style, and basked in adulation during a slow jog around the edge of the track draped in the Jamaican flag.
The win was a perfect birthday gift for his country on the eve of its 50th anniversary of independence from Britain, and will trigger wild celebrations back home.
Bolt joined Carl Lewis as only the second man to go back-to-back in track's biggest race.
Bolt's training partner and fellow Jamaican, Yohan Blake, finished second in 9.75. American Justin Gatlin took bronze in 9.79.
Bolt fell shy of his world record of 9.58 seconds but improved on the 9.69 he ran four years ago in Beijing to enter his name, once again, in the Olympic record book.
After taking half a victory lap around the track, he stopped, kissed the track and gave his now-famous "To The World" pose, pointing both fingers in the air while the fans screamed.
He said: "I was happy. When I went in first round I thought to myself 'I can do this' and I was feeling good.
"I sat in the blocks a bit then but my coach told me to stop worrying about the start and do the business and I did.
"When it comes the championships, I do it. I brought it. I did it.
After winning his silver medal, his compatriot Blake said: "Usain is the fastest man in the world. I have to thank him.
"I've got a silver medal and I've got to be happy with that."
The sell-out 80,000-capacity crowd at the Olympic Stadium were on their feet when the eight finalists, including the four fastest men in the world - Bolt, Gay, Blake and Asafa Powell - lined up.
As the television cameras picked out each racer, the excitement mounted as they reached Bolt in lane seven, dressed in black shorts and the yellow and green singlet of the Jamaican team.
The 25-year-old showed no signs of nerves as he bid to replicate his gold medal showing in the Beijing Games in 2008.
To mass delight, he practised his DJ mixing skills, one hand raised to his ear, and then drew laughter after drawing pretend pistols and reholstering them after pointing them down the track.
As the starter called them to the blocks, Bolt put a finger to his lips to hush the excitable crowd, briefly crossing himself and looking skywards as the television zoomed in and his picture was broadcast on the big stadium screen.
As silence descended, the gun went and Bolt's reaction time from the blocks saw him rocket away, but Gatlin had the edge on his left.
Bolt, however, pushed his huge frame through his renowned drive and transition phase after 50 metres.
Teeth gritted and long legs pumping, Bolt completed what turned out to be a remarkably comfortable victory given the quality and strength of the field.
After Bolt crossed the line, he immediately set off on a lap of victory, a Jamaican flag draped over his shoulders and Blake in tow.
He stopped to perform his customary "bow and arrow" pose at various points, to chants of "Usain, Usain!" ringing around the stadium.
It was a remarkable result for the Jamaican who revolutionised sprinting, and indeed athletics, four years ago in Beijing, setting then-world records when winning the 100 and 200m titles, and also starring in a record-breaking Jamaican quartet in the 4x100m relay.
He left the Chinese capital as one of the most recognisable figures in world sport, unbelievably going on to beat both his individual sprint marks with new times (9.58 and 19.19sec) in the Berlin worlds in 2009.
Bolt lost his world 100m title in Daegu, South Korea, last July to Blake after sensationally false starting in the final, but has fired back in most emphatic fashion.