* Farrington wins shock gold with second run
* Defending champion Bright takes silver
* Clark first woman to win three snowboard medals
American Kaitlyn Farrington stunned three former champions to win the Olympic gold medal in the women's snowboarding halfpipe by the narrowest of margins at the Sochi Games on Wednesday.
The 24-year-old nailed her second run to score 91.75 and claim the title ahead of Australia's defending champion Torah Bright, who was awarded 91.50 for her second effort.
Farrington could barely contain her disbelief at her score and watched nervously as the final six riders completed their runs before she could celebrate her first gold medal at any major event.
American Kelly Clark, the 2002 champion, was awarded 90.75 for the final run of the night to take the bronze and become the first snowboarder to win three Olympic medals after also finishing third in Vancouver.
"I'm just so proud of Kaitlyn, this is her first Olympics so to see her come out and walk away Olympic champion is just amazing," said 30-year-old Clark, who was competing in her fourth Games.
Hannah Teter, who won gold in 2006 and silver in 2010, led after the first run but fell on her second attempt and had to be satisfied with fourth place after compatriot Clark bumped her off the podium.
Bright was, as usual, all smiles and congratulations for her rivals but might consider herself unlucky not to have scored higher with a clean second run, which had a higher degree of difficulty than Farrington's routine.
World champion Arielle Gold of the United States did not even make it to qualifying, falling during her warm-up and pulling out after consulting with medical staff.
Despite disappointment for Teter and Gold, the Americans restored some pride for the nation after the men's halfpipe team, spearheaded by Shaun White, failed to win a medal for the first time in an Olympics on Tuesday.
After the drama of the men's final, Wednesday was a more subdued night at Extreme Park, with the tension only really ratcheting up after Clark's second run when the judges took an age to confirm her score and decide the podium places.
Clark, like Bright, had fallen on her first run and only a little unsteadiness on her landings denied her the chance to win a second gold 12 years after her first.