Olympic champion Defar canters through heat

A slow first heat, won by Kenyan Mercy Cherono, gave the also-rans who followed in heat two a time target to aim for and a good pace ensured all except Georgian Giuli Dekanadze, who was lapped by the field, went through.

Defar, world champion in 2007 but bronze medallist in each of the last two editions, said she had "prepared well" for Moscow, where her task has been made easier with team mate Tirunesh Dibaba, winner of the 10,000 metres, not bidding for a distance double.

"I am ready for the final," Defar said. "It will be a battle between Kenya and Ethiopia again."

Kenya's Asbel Kiprop and Silas Kiplagat battled it out for 1,500 metres gold and silver two years ago in Daegu, South Korea, and both eased into Friday's semi-finals with heat wins.

Kiprop is favourite to defend his title after clocking a stunning 3:27.72 in Monaco on July 19, putting him fourth on the all-time list, but he guarded against complacency.

"I never under-estimate anyone," the tall Kenyan said.

In women's hammer qualifying Germany's Betty Heidler was a notable casualty, the 2007 world champion and twice silver medallist putting her failure to reach Friday's final down to "technical problems".

Guts, guile and no lack of self-belief propelled Irishman Robert Heffernan to 50km race walk victory.

While the Russian enjoyed the cheers of a nation, the 35-year-old Heffernan had the one supporter who mattered most as he scooped Ireland's first world gold in 18 years.

"My wife is here with me and we are so happy," he said with understatement after denying the hosts a clean sweep of the walks after they took gold in both 20km events earlier in the week.

"I believed I could be the winner," he added after a career of near medal misses.

"It was very tough but I tried to stay positive. The last 10km are like a crucifixion."

With no evening session on Wednesday as the nine-day championships take a breather, the walk and a handful of qualifying represented thin fare.

Two long-jump champions at opposite ends of their careers experienced contrasting fortunes, with Briton's Olympic winner Greg Rutherford failing to reach the final and 'golden oldie' Dwight Phillips continuing his dream of a last hurrah.

Rutherford declared himself fit at the last minute for the championships after suffering a hamstring tear five weeks ago, but his best of 7.81 metres on Wednesday fell short.

"I just didn't have what it took out there today. Believe me, I gave everything," the 26-year-old said.

"My last training session, I had it two days ago and it felt fantastic."

American Phillips, 35, postponed his retirement for a year to try and become the first US athlete to win five individual world championship titles in the same event.

"Today my body felt great. Once you are in the final anything can happen," Phillips, world champion in 2003, 2005, 2009 and 2011, said after a season's best effort of 7.95.