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Video - Watch closing stages of the race
World champion Olga Kaniskina battled through heavy rain to set a new Olympic record and claim gold in the women's 20km walk.
The Russian led the race from start from finish and had a 20-second lead before the athletes left the Bird's Nest stadium at the start of the race.
She finished in one hour 26 minutes and 31 seconds, 36 seconds ahead of second placed Norwegian Kjersti Platzer.
Britain's Johanna Jackson finished 22nd in 1:31:33, a new British record.
"I cannot believe it," said the 23-year-old from Middlesbrough. "I walked the race of my life and I am over the moon to have broken the record in the Olympic final.
"I did not get the top 20 position I wanted but it was too fast. Now I want to build for 2012. I am still young for this event."
Kaniskina insisted the only reason she had not broken the world record set by compatriot Olimpiada Ivanova in 2005 was the rain.
I was so glad when I woke up and it was pouring with rain
But she said the weather had not otherwise affected her performance.
"It had no influence on me," she said. "It was better than a sunny and hot day. I didn't feel it was very slippery.
"I was in good condition. I think my regular training is the most important factor contributing to my victory."
Jackson added that the weather had helped rather than hindered her.
"I was so glad when I woke up and it was pouring with rain, although I wouldn't have minded hot conditions as I may have been able to pick a few more off."
The bronze medal went to Italian Elisa Rigaudo after a late surge through the field.
I'm a bit disappointed to be 33 seconds away from the medals, but when I saw the pace and how quickly it was going I knew it was too fast
Ireland's Olive Loughnane
Ryta Turava of Belarus led the chasing pack until the final kilometres but, struggling with exhaustion, she dropped back after being forced to stop several times.
Ireland's Olive Loughnane finished seventh in a new personal best of 1:27.45.
"If you had told me last night I'd have done 87:45 I would have said I had to make the medals," she said.
"Of course I'm a bit disappointed to be 33 seconds away from the medals, but when I saw the pace and how quickly it was going I knew it was too fast.
"I did amazingly well and couldn't have done any more. I was prepared for it to be hot today but I smiled when I saw the weather."