After opening with a false start in the 100 final last Sunday, Usain Bolt again produced the amazing in his closing race of the world championships - anchoring Jamaica to a world record yesterday in the 4 x 100-meter relay. When the first three runners passed the baton, Bolt seized the moment.

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

And when Bolt is convinced, the clock usually obliges.

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.

“For me, it was just to go out there fast,’’ Bolt said. “We did just that.’’

One day after winning gold in the 200, Bolt was devastating down the home stretch of the relay and threw his 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. I’m proud of myself.’’

There was none of the performance anxiety that pushed him into a false start in the 100, 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. He left with two and a world record.

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

On the 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 to 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.’’

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

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

Tatyana Lysenko won the women’s hammer throw, putting Russia in second place in the standings with nine gold and 19 medals overall.

Britain got some good news ahead of next year’s London Olympics, with Mo Farah holding off Bernard Lagat of the US 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 that went wrong for Kenya. From the starting gun to the 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 standings.