PHOTOS: Isinbayeva vaults to fairytale third world gold

Yelena Isinbayeva, the greatest woman pole vaulter of all time, thrilled a partisan home crowd roaring her every jump when she landed the third and probably last world title of her illustrious career in Moscow on Tuesday.

The Russian, twice Olympic champion and world outdoor record holder, was the only vaulter to clear 4.89 meters.

It was a season's best leap for the 31-year-old, the first woman to clear the revered five metres barrier, who said before the championships that she would retire.

American Olympic champion Jenn Surh took silver and Cuban Yarisley Silva bronze.

Both failed at 4.89 after clearing 4.82.

After a nervous start when she failed with her first attempt after entering the competition at 4.65, a measure of her confidence with her rivals already up and running, Isinbayeva grew in stature.

With a chorus of "Yelena Yelena" reverberating around the Luzhniki stadium, the biggest crowd of a poorly attended championships so far, each clearance was greeted by a cacophony of approval.

Isinbayeva rewarded the support with punches in the air and squeals of delight.

When gold was assured she ran to the crowd and embraced her coach.

Milking the moment and urging the crowd to raise the decibel level further, she asked for the bar to be raised to 5.07, one centimetre above the world record she set in 2009.

Three unsuccessful attempts followed but it could not spoil the former gymnast's celebrations as she set off for a lap of the track which featured a cartwheel and back-flip.

Isinbayeva was virtually unbeatable between 2003 and 2008, when she kept raising the bar higher and higher, often by a centimetre at a time.

But plagued by injury and poor form and after failing to register a height in the 2009 world championships, she decided to take a break from the sport, returning after an 11-month absence.

She was again outside the medals at the 2011 worlds but took bronze at last year's London Olympics.

A grimacing Mohammed Aman hurtled to the front in the final 10 metres to become the first Ethiopian to win an 800 metres world title on Tuesday.

Aman, the only man to beat world record holder David Rudisha since 2009 and pre-race favourite in the absence of the injured Kenyan, pipped American Nick Symmonds for victory in 1:43.31. Djibouti's Ayanleh Souleiman was third.

It was Ethiopia's first world gold at a distance below 5,000 metres.

Olympic champion Elena Lashmanova overcame confusion over where the finish line was to lead home a Russian one-two in the women's 20-km race walk.

World record holder Lashmanova, 21, secured a first world title but had only three seconds to spare at the line over team mate Anisya Kirdyapkina after twice almost breaking stride on her final lap because she did not know where the race ended.

"The judges didn't really explain to us that we should do one lap before the home straight and finish," she said.

"That's why I stopped for a second in the stadium, but I quickly understood I should keep going."

Lashmanova clocked 1:27:08 on a hot morning in the capital, getting a rousing reception as she entered the Luzhniki stadium. A fast-closing Kirdyapkina could not quite close the gap despite her younger rival's slip-up, while China's Liu Hong took bronze in 1:28:10.

LaShawn Merritt returned the United States to the top of the 400 metres podium at the world championships on Tuesday with a commanding performance as defending champion Kirani James faded badly to finish a surprise seventh.

Merritt took the race on from the gun and went out hard over the first 200 but, unlike James, the American had plenty left in the tank coming into the home straight to seal victory in a world-leading 43.74 seconds.

Compatriot Tony McQuay was second in 44.40 and fast-finishing Luguelin Santos of Dominican Republic edged out Belgium's Jonathan Borlee for bronze in 44.52.