Russian Elena Lashmanova swept from behind during the second half of the race Saturday and set a world record in winning the Olympic 20-kilometer walk. Lashmanova walked through the streets of central London in the time of 1 hour, 25 minutes, 2 seconds -- lowering by 6 seconds the world mark set 19 months ago by countrywoman Vera Sokolova. Defending Olympic champion Olga Kaniskina of Russia held the lead for much of the race before finishing second just 7 seconds behind Lashmanova. China\'s Qieyang Shenjie was another 7 seconds back in third place. At the midway point of the walk, Lashmanova was 43 seconds behind. She slowly made up ground and passed Kaniskina in the final kilometer. Lashmanova\'s victory completed a gold medal sweep for Russia in the long-distance walks Saturday. Russia\'s Sergey Kirdyapkin won the men\'s 50-kilometer event earlier in the day while setting an Olympic record. He finished the distance in 3:35.59, a minute in front of Jared Tallent of Australia. China\'s Si Tianfeng, who took an 18-second lead early in the race, finished third.