Firova turns the heat up on Dunn ahead of 400m final

From David Jordan, Sportbeat, in Doha

 RUSSIA'S Tatyana Firova turned the heat up on hot favourite Debbie Dunn of the USA in the 400m semi finals at the World Indoor Athletics Championships in Doha.

DANGER MAN: American Bershawn Jackson claims Ireland's David Gillick is his chief rival for the 400m title at the World Indoor Athletics Championships (Getty Images)

The two-time Olympic relay silver medallist won her morning heat in a pedestrian time of 52.67 seconds but romped through her semi final in 51.36 to give Dunn, the fastest woman in the world this year, a gentle reminder of her presence in Qatar.

Dunn, who topped the World Championships relay podium in Berlin last summer, has clocked 50.86 this season and while she was in dominant form in her morning heat, she coasted through the semis in 52.08.

Joining those two in the final will be Jamaica's Novlene Williams-Mills, who clocked a season's best of 51.77 but there was no place in the final for the USA's Deedee Trotter, who could only finish fifth in her semi.

In the men's 400m semi finals, Ireland's two-time European champion David Gillick gave red-hot favourite Bershawn Jackson a run for his money despite a stumble on the second lap, before the American came home in 46.13 - 0.02 faster than Gillick.

Jackson said: "I think David Gillick is one of the major challenges for the final. He has got a very strong finish and is very determined. It is good. But this is my game.

"I feel very strong, I train very hard every day and I am prepared to distribute a great entertainment to the people here. The 1st round was pretty hard, the second was better but even like a final to me."

And Chris Brown of the Bahamas led the way in the second semi, crossing the line in 46.64 while Jamaica's Ricardo Chambers could not fight his way back from being knocked off balance in the closing stages.

Meanwhile, Great Britain's Richard Buck could not book his place in the final and come home fifth in his semi in 47.70.

After four events of the heptathlon, Olympic decathlon champion Bryan Clay leads the way by just a single point from Russia's Aleksey Drozdov.

Clay posted the fastest time in the 60m sprint and followed that up with finishes of sixth, third and sixth in the shot put, long jump and high jump respectively.

That gave Clay a combined total of 3549, one more than Drozdov and 72 ahead of third-placed Oleksiy Kasyanov.

Athens 2004 Olympic gold medallist and former two-time champion Roman Sebrle is currently fourth on 3465 while world champion Trey Hardee of the USA is in fifth place.

Aviva has been proud to have helped and supported the Aviva GB & NI junior, senior and disability teams as they prepare for all major events and championships since 1999. Visit www.aviva.co.uk/athletics for more information