DAEGU, South Korea — In one whirlwind week, Usain Bolt turned the biggest disappointment of his career into another golden show capped with a world record that even he long believed was not within him this year.

After opening with a false start in the 100m final last Sunday, Usain Bolt again produced the amazing performance in his closing race of the World Championships — anchoring Jamaica to a world record in the 4×100-metre relay.

When the first three runners passed the baton, Bolt suddenly saw the unexpected become reality.

“I said, ‘Why not give my all’. I kept saying: ‘I can do this. I can do this,”‘ Bolt said.

And when Bolt is convinced, the clock usually obliges.

One day after winning gold in the 200, Bolt was devastating down the home stretch of the relay and threw his yellow-clad chest across the line for a time of 37.04 seconds — the only world record in nine days of competition.

“This record was a great achievement,” Bolt said. “I finished the championships on a good note so I’m proud of myself.”

Fittingly, Jamaica’s yellow-green-and-black flag was the last one rising into the night over Daegu Stadium, and Bolt spread his giant arms wide to soak in the occasion with all his might.

There was no more of the performance anxiety that pushed him into a false start in the 100m, only a sheer release of power as he coasted down the stretch for an overwhelming win over France and Saint Kitts and Nevis.

He came looking for the same three gold medals he won at the 2008 Beijing Olympics and 2009 World Championships but left with only two and a world record.

The United States was out of it because of a fall, but no one could have gotten close to a Jamaican team anchored by Bolt.

Ahead of the race, Bolt was already slapping the “JAM” on his bib in pride, and although he was far from his best, he came through with a world record at the end of a season when he only centred on titles and victories, not times.

He got all the help he needed from his three teammates — a lightning start from Nesta Carter and a good handover to Michael Frater before Jamaica’s golden duo was up. Yohan Blake, the 100m champion in Bolt’s absence, powered through the final bend, with Bolt already getting his giant stride going before he took the baton.

Even Carter had no idea the team could do it.

“We weren’t really going out to break the world record,” Carter said.

Without the injured Asafa Powell, Bolt anchored the team for the first time in a major competition since he took the world by storm at the Beijing Olympics.

Running with the determination of a record beater, he gritted his teeth over the final metres, crossed the line and threw the glittering purple baton high in the air once he realised their three-year-old record of 37.10 was gone.

Seconds later, the showman took over again. He started dancing to the delight of the 45,000 crowd at Daegu Stadium, which had to wait until the last second to finally see a world record.

In the blur of the best Bolt braggadocio, it was almost forgotten that Blake also left with two gold medals and a world record performance.

On a final day of seven finals, one silver medal also stood out.

Caster Semenya failed to defend her 800 title, faltering late down the finishing straight to allow Mariya Savinova of Russia get the gold. Silver, however, was better than many expected as the South African showed glimpses of her powerful running that made her the dominating athlete over the distance two years ago, before a gender controversy sidelined her for a year.

“I achieved what I wanted, which was to get back to the podium,” the 20-year-old Semenya said. “I don’t talk about the past. I’m still young and I have to focus on the future.”

Kenia Sinclair of Jamaica finished in a time of one minute, 58.66 seconds to place seventh of eight runners.

Allyson Felix added another gold to bring her collection of titles to a women’s record eight over four championships. The American ran the second leg of the winning 4×100 relay, one day after getting gold in the 4×400, too.

Veronica Campbell Brown narrowly failed to catch newly-crowned world 100 champion Carmelita Jeter, and previous world champions Jamaica had to settle for the runner-up position behind the United States.

A weak third leg from Sherone Simpson following strong runs from Shelly-Ann Fraser-Pryce and Kerron Stewart left Campbell Brown with plenty of work on the anchor leg.

But the dynamic Jamaican sprint darling vigorously chased Jeter in the final straight, taking her side to the silver in a national record time of 41.70 behind the Americans, whose 41.56 was a world-leading mark for the year.

“We executed as best as we could,” said Campbell Brown. “It is the biggest thing for us. We are happy for the national record. It is great that we were able to accomplish that.

“We broke away with our heads high because we are the national record-holders in the 4×100 for Jamaica. That is huge.”

Trinidad & Tobago, whose side included Kai Selvon, 100 bronze medallist Kelly-Ann Baptiste, Semoy Hackett, and Michelle-Lee Ahye, narrowly missed out on the bronze, clocking 42.93, and were 0.35 slower than third-placed Ukraine.

With Christian Taylor winning the triple jump, it left the United States at the top of medal standings with 12 gold and 25 overall.

Britain got some good news ahead of next year’s London Olympics, with Mo Farah holding off Bernard Lagat of the United States to win the men’s 5,000. Farah also won silver in the 10,000 last weekend.

It was about the only middle and long distance race which went wrong for Kenya.

From the starting gun to yesterday’s last day, Kenya dominated. Yesterday morning, Abel Kirui led teammate Vincent Kipruto to yet another 1-2 finish in the men’s marathon.

The defending champion won by the biggest margin in championship history, and after finishing the race in 2:07:38, he had to wait 2:28 to welcome Kipruto in a sweaty embrace.

It left Kenya with seven gold and 17 medals overall for third place in the medal standings.

Jamaica finished fourth on the medals table with nine in total, including four gold, four silver and one bronze.

— Observer/AP/CMC