UPDATE 3-Olympics-Biathlon-Neuner hits the turbo to take gold

* Barnstorming finish earns Neuner second gold medal

* Zaitseva edges out Hauswald to snatch silver (Adds detail, further quotes)

By Mark Lamport-Stokes

WHISTLER, Feb 21 (Reuters) - Germany's Magdalena Neuner was in total disbelief after winning her second gold of the Vancouver Olympics and third medal overall with a turbo-style finish in the women's biathlon 12.5km mass start on Sunday.

The six-times world champion, who also sealed victory in the 10km pursuit, recovered from a shaky first round of shooting to complete the twisting course at Whistler Olympic Park in 35 minutes 19.6 seconds.

In dazzling sunshine, the 23-year-old Neuner began smiling a few metres before she crossed the finish line with her arms raised in triumph, edging out Russian Olga Zaitseva by 5.5 seconds.

Germany's Simone Hauswald, who led after the second round of prone shooting, had to settle for the bronze after being pipped by the Russian in a tight sprint finish.

"I think I need to sit down for a while before I fully realise what I've done," a beaming Neuner told reporters. "It's not sunk in yet.

"I knew I could get a medal but now I have three and this is just unbelievable. I need days or weeks to realise this."

Neuner, who in 2008 became the youngest ever women's World Cup overall champion, knew she was back in the medal hunt after shooting clean in the final round of standing.

"All of a sudden, there was only Simone and the Russian (Zaitseva) in front of me so I started the turbo," said the customs officer, who also scooped Olympic silver in the 7.5km biathlon sprint in the Whistler mountains.

Neuner surged into an early lead after the three-row massed start, the skiers looking like giant stick insects as they bobbed and weaved their way along the uphill stretches.

SLID BACK

However, the German missed once in the first round of prone shooting and slid back into 17th spot while Hauswald took over at the top after making no mistake with her first 10 targets.

Hauswald, competing in her first Olympics, faltered with two misses in the first session of standing shooting to surrender the overall lead to veteran Russian Olga Medvedtseva.

Zaitseva, who won gold in the 4x6km relay at the 2006 Turin Games, charged ahead with a flawless display in the last shooting round before Neuner regained control.

The German had clawed her way back from eighth place after the third session of shooting and she surged ahead of the pack over the final 2.5km stretch.

"After the last round of shooting, I was emotionally drained," Zaitseva said. "It was really hard for me and I was out of breath.

"But I attacked during the last stretch and ... at the end of it I felt really great about myself. What I won today was an Olympic medal, whether it is gold, silver or bronze doesn't really matter. I own it. I won it."

With German flags waving in the packed stadium and her supporters sounding horns and ringing cowbells, Neuner skated triumphantly to the finish line.

World Cup leader Helena Jonsson of Sweden has failed to produce her best at the Vancouver Olympics and came home 10th on Sunday.

(Editing by Miles Evans; To query or comment on this story emailsportsfeedback@thomsonreuters.com)