USA’s Allyson Felix fulfilled all the promise of her brilliant youth to become the youngest ever world 200m champion in Helsinki this evening.

The 19-year-old produced a stunning display of sprinting to win the gold medal in 22.16, coming from behind in the home straight to overhaul France’s Christine Arron and Jamaica’s Veronica Campbell.

“Coming off the curve I was a little bit worried because I realised that Christine and Veronica had started very fast,” she said. “But I tried to give it all I had and I knew that I usually am strong in the end.”

Felix’s team-mate Rachelle Smith also produced a stunning finish to come from fifth with 50 metre to go take the silver in 22.31, just outdipping Arron on the line.

Smith’s medal was extra sweet as she had to overcome an injury earlier in the week. “It was an awesome race,” said Smith. “This is unbelievable. At the beginning of the week I could hardly walk because I had a sudden ache in my left ankle.”

Arron was given the same time as Smith but had to be satisfied with her second bronze medal of the championships. “I feel I could have done better because I was a little tired at the end,” she said. “But I still ran a season’s best. I know I will leave these championships with at least two medals, so I am very much satisfied.”

Campbell, the Olympic champion and the 100m silver medallist here, was left without a medal. She had seemed virtually invincible at this event until Felix ended her four-year winning streak in London last month.

“I ran a really good curve then coming into the straight I just do not know what happened,” she said. “The energy was there but then I realised that I was over in the wrong lane and that drew all my attention away and messed up my rhythm.”

In Athens last year Campbell had been the quickest in every round to the final. This time she took a more relaxed route, and perhaps paid for that tactic because she was drawn in lane seven, outside all her rivals.

As in the 100m, Arron was the quickest through all the rounds here but again she appeared to feel the tension when she reached the final stage. On the start line she looked nervous. Drawn in lane five, she stood with a furrowed brough and couldn’t raise a smile when her name was announced to the crowd, just a cursory wave. The grinning Felix, one lane outside her, appeared much more relaxed.

When the gun went, Arron got a good start and was quickly up on Felix. Campbell was also out fast and these two came into the straight almost together, Arron perhaps marginally ahead. For a few strides Campbell appeared to have the edge, then Arron pulled away.

But in the lane between them Felix was timing her charge to perfection. She passed Arron 30m from the line as the Frenchwoman began to feel the strain and Campbell started to falter.

Felix lengthened her graceful stride as she eased away, and punched her fist at the ground as she crossed the line, mouthing the words, ‘Yes, yes.’ The gold was hers.

Behind her, Smith, in lane four, had left it late but found her legs in the last quarter of the race. She made up three metres on Arron, passing Campbell and clinching the bronze.

The American 1-2, the first ever in this event, comes after the USA took the first four positions in yesterday’s men’s final. At just 19, Felix now has a world gold medal to go with her Olympic silver.

“It feels very good to be world champion,” she said. “But I still have the relays to go.”

Arron and Felix impress in semis

Christine Arron must wish every race was a heat. The Frenchwoman is becoming expert at running through the rounds in the style of a champion. Whether she can actually become a champion we’ll have to wait until tomorrow to see.

She looked the woman to beat right through the 100m rounds but couldn’t hold it together for the final when she was let down by a bad start and could only take bronze. That is less of a problem in the 200m, of course, and if her performance in the semi-finals tonight is anything to go by she will again be in the medals, at least.

Arron was by far the quickest of the 200m semi-finalists this evening. On another day more suited to wet weather gear and ski hats than world class sprinting, she cut through a -2.7 headwind and left the American pair of LaTasha Colander and Rachelle Smith in her wake to win the first race.

Arron ran a smooth bend to enter the straight ahead and pulled away through the puddles to clock 22.45. Colander, Smith and the Cayman Island’s Cydonie Mothersill were the other qualifiers.

Arron won’t have it all her own way, however.

The Olympic gold and silver medallists both qualified from the second semi, won by an equally impressive looking Allyson Felix. Although the powerful Jamaican Veronica Campbell led off the bend, it was Felix who looked more relaxed, gracefully striding through the water-littered track into a biting -4.0m/s wind for an easy win in 22.90.

After her exertions in the 100m final on Monday, Campbell took it easy in the heats yesterday morning. Although she was an easy qualifier here, she seemed to be trying this time, but was actually caught on the line by Belgium’s Kim Gevaert, running 22.97 to Campbell’s 23.02.

In last year’s Olympic Games, Campbell became the champion after running quickest through all the rounds and setting a world leading time in the semi-final.

Russia’s Yuliya Gushchina, who had blasted through the cold winds in yesterday’s first round, struggled through the rain and wind this evening but made the final in fourth place in 23.10.