Felix powers to world 200m gold

American teenager Allyson Felix fulfilled her enormous talent by powering to the world women's 200 metres title yesterday.

The 19-year-old, the Olympic silver medallist, overcame a slow start to surge through to victory in 22.16 seconds.

Team-mate Rachelle Boone-Smith recorded 22.31 to take silver with France's Christine Arron winning bronze with the same time.

But, defending champions the United States failed to finish their first round heat in the men's 4x100 relay.

The baton was dropped in a bungled changeover between lead-off runner Mardy Scales and Leonard Scott.

The 200m women's final was expected to be a showdown between Felix and Olympic champion Veronica Campbell but the Jamaican, who veered out of her lane just after the bend, ran out of gas with the gold medal in sight.

Campbell, who had her five-year winning streak at the distance ended by Felix last month, led with 30 metres to go but faded to fourth.

Arron, bronze medallist in the women's 100 final, flew out of the blocks and on the shoulder of Felix, one lane outside her, turning into the straight but the smooth-striding American had left enough in the tank to turn on the power.

"I was trying to give it all I had but I knew that I could take it up," said Felix. "I just had to rely on all the work I put in this season."

American Kelli White, who did the 100-200 double at the 2003 Paris world championships, lost her titles after admitting taking THG among a variety of other drugs.

White's 200 gold medal went to Russian Anastasiya Kapachinskaya, who then tested positive for the steroid stanozolol at last year's Budapest world indoor championships.

The elimination of the US team from the relay means world 100 and 200 champion Justin Gatlin cannot win a third gold medal.

"I put all the blame on myself," said Scott.

"The bottom line is that we practise on these sticks every day and they are supposed to get through the zone and it slipped out of my hand so it was my fault.

"I can't even tell you how it came out of my hand. These things happen."

Former Olympic and world champion Maurice Greene, who was running the anchor leg for the Americans yesterday, said Scott had appeared to take the baton.

"Then it slipped out of his hand," he said.

Ladji Doucoure sealed France's first gold at this year's world championships by winning the men's 110 metres hurdles title.

European indoor champion Doucoure flashed across the line in 13.07 seconds, one-hundredth of a second in front of Chinese Olympic champion Liu Xiang.

American Allen Johnson, who was bidding to win a record fifth world track title, took the bronze after leading for most of the race before Liu moved ahead just before the finish.

World leader Doucoure, 22, was among the favourites to win gold as the only man alongside Johnson to run under 13 seconds this season.

The Frenchman finished last in the Olympics final last year after smashing into a hurdle.

Russian wins 50km walk

Sergey Kirdyapkin filled the void left by Pole Robert Korzeniowski to lead home a Russian one-two in the 50km walk.

The 25-year-old set a relentless pace, leading from early on to finish in warm conditions and take gold in a personal best of three hours, 38 minutes and eight seconds.

Olympic bronze medallist Aleksey Voyevodin kept tabs on his compatriot until halfway but was shaken off and had to settle for silver in 3:41:25. Italy's Alex Schwazer, seventh at the halfway stage, rallied to take bronze in 3:41:54.

Triple world and Olympic champion Korzeniowski, the greatest walker in history, retired after winning his third Games 50km walk title last year.

China, boasting athletes with the three fastest times this year, failed to mount a title challenge with Zhao Chengliang finishing the best of their three walkers in fifth place.

Olympic champion Jeremy Wariner set a personal best of 43.93 seconds to win the world men's 400 metres title last night.

American Andrew Rock was second in 44.35 and Canadian Tyler Christopher took the bronze in 44.44.

In women's hammer, Russia's Olga Kuzenkova finally won the world title after finishing second in the last three IAAF championships.

The Olympic gold medallist took the lead in the penultimate round, with 74.03 metres but saved her best till last with a throw of 75.10.

Yipsi Moreno, of Cuba, took the silver with 73.08, missing out on her third successive world title. World record holder Tatyana Lysenko of Russia was third with 72.46.