British athlete Christine Ohuruogu has come storming through to win Olympic gold in the 400 metres. The Londoner, who won a legal battle to run at the Games, was in fourth place with 100 metres to go but she timed her sprint finish perfectly. Sanya Richards of the United States had a huge lead after 300 metres but she tired as expected and Ohuruogu cam through to win in 49.62 seconds. Ohuruogu adds the Olympic gold to her world championship title over 400 metres. Like Dwain Chambers, she was banned from the Great Britain Olympic team for life after being given a 12-month drugs ban in 2006 having missed three out-of-competition tests. However, Ohuruogu fought against the ban because she has never tested positive for any banned substance. Dick Pound, chairman of the World Anti-Doping Agency, backed her bid to have the ban overturned. On November 27 last year the BOA announced she had been successful and would therefore be allowed to compete in Beijing.