China's Sun Yang reacts after he won gold in the men's 1500m freestyle final during the swimming event at the London 2012 Olympic Games yesterday in London.

Sun Yang of China smashed his own world record in racing away to win the men's 1500-metres freestyle gold medal at the Olympics yesterday.

Sun was under world record pace all the way to hit the wall in 14min 31.02secs, bettering his own mark of 14:34.14, set at last year's world championships in Shanghai.

Ryan Cochrane of Canada took the silver medal in 14:39.63, with defending champion Oussama Mellouli of Tunisia taking bronze in 14:40.31.