Jamaican Usain Bolt regained his world 100m title after taking gold in 9.77 seconds on Sunday at the World Athletics Championship in Moscow.

American Justin Gatlin took silver in 9.85 and Jamaican Nesta Carter bronze in 9.95.

World record holder and Olympic champion Bolt was disqualified from the 2011 final won by compatriot Yohan Blake after he false-started.

"My legs were sore after the semi-finals, I don't know why, but the world record wasn't on so I came out just to win" - Usain Bolt

Bolt lit up the Luzhniki Stadium by blazing to gold.

The world record holder defied the pouring rain to storm to victory on a drenched track in a revised time of 9.77 seconds, his best time of the year.

The medal is Bolt's fourth individual world gold, and his second individual world 100m gold.

Bolt performed all his customary pre-race preening, pretending to hold up an umbrella, all part of the show from the born entertainer but when it came to the crunch he was, as always, ice cold.

He was out of the blocks well and, just as it looked as if Gatlin, in the lane inside him, might be closing, he pulled clear to reclaim the title he lost after a false start in the final in Daegu two years ago.

This final had been headed for a mouthwatering showdown between Bolt and a rejuvenated Tyson Gay, before the latter's failed drug test sent shock waves through athletics. Former world record holder Asafa Powell's failed test was confirmed hours later and the sport was on its knees.

So it was perhaps apt that tonight's race was a head-to-head between Bolt, the saviour of the sport, and two-time former doper Justin Gatlin.

The American had beaten Bolt by a whisker at a Diamond League meeting in Rome at the start of the season, but the world stage is where the world record holder feels at home.

Lightning flashed overhead ahead of the final, but, with Bob Marley's 'Three Little Birds' playing before they took to their blocks, Bolt delivered.

Bolt told the press: "I am happy but I wanted to do better.

"My legs were sore after the semi-finals, I don't know why, but the world record wasn't on so I came out just to win.

"Back in Jamaica, they do not expect less than that from me. They always expect me to dominate."

Bolt had sauntered through his semi-final in 9.92 earlier tonight and his final time was impressive given the terrible conditions.

Gatlin admitted he was too good.

He told Radio Five Live: "I'm getting closer, I'm very happy with my race.

"The last 30m I got long. In Rome I was able to step down all my steps and do my race which I didn't do tonight.

"He (Bolt) has been working on his start - in Rome he had the best reaction out of everybody and he is 6ft 5in. I had to make sure I was beating him to 50m.

"We saw the lightning and thunder in the warm up and we said that normally they would postpone this, but it is Moscow and Russia and they wanted this."