The floodlit drama in the 110- meter hurdles was exactly what the 13th world championships needed to dispel a gloom which, like the ever-present mist on Daegu's mountains, had lingered around the stadium after the shock of Usain Bolt losing his 100m crown.

A victim of the one-false-start-and-you're-out rule, Bolt was disqualified on Sunday night and his Jamaican understudy Yohan Blake crowned champion in a major anti-climax. The world's fastest man took his time responding to the disqualification, waiting around 18 hours to make any statement.

When he did respond publicly, Bolt said very little. But what was there to say about a perhaps overly harsh rule which is sure to cause plenty of soul-searching among the sport's highest echelons?

"Firstly, I would like to congratulate my teammate Yohan Blake and the other athletes who won the medals," a statement released by Bolt's management team read. "Of course I am extremely disappointed not to have had the chance to defend my title due to the false start. However, I have to move on now as there is no point to dwell on the past."

Allyson Felix will also need to move on as her dreams of completing an unprecedented women's 200-400m double at a worlds disappeared when she was beaten in the 400 final by Amantle Montsho.

Montsho could not wipe the smile from her face after landing Botswana's first gold at a world championships.

"I know Allyson is a good athlete and she is fast... I felt when she was coming, but I managed to hold on," Montsho said.

Felix was sanguine in defeat.

"On the home straight I definitely felt I still had a chance," she said.

"I gave it all and tried to move my arms. I cannot be too disappointed with my silver medal. I still have the 200 meters and the relays coming up."

Carmelita Jeter put a smile back on the faces of Team USA in the night's last final, racing to gold in the women's 100 meters.

She finished in 10.90 seconds, beating Jamaica's Veronica Campbell-Brown by 0.07 seconds with Trinidadian Kelly-Ann Baptiste third.

"I have been working really very, very hard. And today it paid off," Jeter told reporters. "My coach showed me that I was ready to get the gold medal, to stop the Jamaican predominance in the sprint."

In field events, Koji Murofushi earned a surprise gold medal in the hammer with a throw of 81.24 meters to give Japan its first title of the championships, while Poland's Pawel Wojciechowski leapt to gold in the pole vault, ahead of Cuban Lazara Borges.

Delighted New Zealander Valerie Adams took her third successive women's shot put world title. Nadzeya Ostapchuk of Belarus was second with 20.05 and Jillian Camarena-Williams of the US took third with 20.02.