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Video - Chinese reserve wins 72kg gold
Chinese wrestler Wang Jiao, who only competed because of injury to the country's first choice, defeated Stanka Zlateva of Bulgaria to take 72kg gold.
Wang pinned Zlateva, the favourite, with three seconds remaining in the first period of the final.
Wang, 2007 world junior champion, replaced Athens champion Wang Xu after she injured a shoulder in training.
The bronzes went to Japan's five-time world champion Kyoko Hamaguchi and Agnieszka Wieszczek of Poland.