Daegu, South Korea: Sprint superstar Usain Bolt brought the world championships to a thrilling climax Sunday as his Jamaican team smashed the world 4x100m relay record on the last night of action in Daegu.

It was Bolt's second gold of the worlds after winning the 200m crown and marked a fairytale ending for the sprinter, who on only the second day of the championships saw his 100m dream shattered when he false-started.

Jamaica's team of Nesta Carter, Michael Frater, Yohan Blake and Bolt got off to a flyer and never looked like being caught, Bolt stretching every sinew to cross the line in 37.04sec to beat their previous world record of 37.10 set in the final of the Beijing Olympics.

France took silver and St Kitts and Nevis bronze.

Main challengers the United States failed to finish after Darvis Patton tumbled to the ground and could not get the baton to Walter Dix who was running the anchor leg.

A delighted Bolt danced on the track and pretended to strip his singlet off in front of a packed crowd, just a day after wowing spectators with the fourth fastest 200m run of all time as he rebounded from his 100m disappointment.

"For me it was just to go out there fast," said Bolt. "We did just that. I am proud of my team, I'm happy with myself.

"I enjoyed being the anchor," he said in reference to the fourth leg normally run by Asafa Powell, who missed these worlds with injury.

Elsewhere on the track, Mo Farah ensured Olympic hosts Britain ended the worlds on a high with 5,000m gold.

Farah won a thrilling battle down the home stretch to take gold, putting behind him the frustration of just missing out on the 10,000m title.

Ethiopia's Dejen Gebremeskel took bronze after his team-mate Imane Merga was disqualified for stepping inside the curb.

Farah, the first British athlete to win a global long-distance event, said: "It hasn't sunk in yet. I wanted to put things right after the 10k. It was key today to wind it up and not let anyone go past me and then dig in after that.

"I knew Bernard Lagat coming up from 1500m would have the speed."

Russia's Mariya Savinova denied Caster Semenya a second consecutive women's 800m title, nipping past the controversial South African for gold.

The reigning world indoor and European champion timed her run to perfection, coming from near the back of the pack at 600m to clinch the victory in 1min 55.87sec.

Semenya, looking to bury controversy over her true gender, took silver with Kenya's 2007 champion Janeth Jepkosgei claiming bronze.

"The race was pretty good," said Semenya. "Even though I got a silver today I really enjoyed it. It was better than two years ago. I know I won gold in Berlin, but I am feeling much better today."

After her win in Berlin in 2009, Semenya found herself the target of seedy allegations that saw her cast into limbo because of doubts over her gender.

But she was cleared by the sport's world governing body, the IAAF, and has since been largely accepted by her peers.

Earlier Abel Kirui romped to marathon gold on the streets of downtown Daegu to seal a marathon double for the east African powerhouse.

In yet another show of distance running power by Kenya, Kirui crossed the line in 2hr 07min 38sec, nearly two-and-a-half minutes ahead of team-mate Vincent Kipruto -- the biggest winning margin in world championships history. Ethiopia's Feyisa Lilesa took bronze.

The 29-year-old, who did a celebratory dance after crossing the finishing line, said: "It is really very, very nice for me. It was emotional. I find myself sometimes dancing, rejoicing because it was a very great day."

America's women took gold in the 4x100m relay ahead of Jamaica and the Ukraine and Christian Taylor of the United States won the men's triple jump, pipping Britain's defending champion Phillips Idowu. American Will Claye claimed bronze.

Russia's Tatyana Lysenko won the women's world hammer throw with a best of 77.13m, ahead of Germany's Betty Heidler and China's Zhang Wenxiu.

The United States topped the medals standings with 12 golds, ahead of Russia (nine) and Kenya (seven).

(Agencies)