2011 World Championships in Athletics – Women's 400 metres

The defending champion was Sanya Richards-Ross and despite her poor form earlier in the season, she ran 49.66 seconds in London just three weeks before the championships.

Three-time 200 m world champion, Allyson Felix, was also challenging for the 400 m title, while Amantle Montsho (ranked third that year) had five straight wins on the Diamond League circuit.

Jamaica's Rosemarie Whyte, Novlene Williams-Mills and Shericka Williams were also contenders, as was 2009 third placer Antonina Krivoshapka.

For the bronze medal, Anastasia Kapachinskaya was faster down the final 80 metres to pull away from Francena McCorory, who had run her personal best in the semi-finals.

[2][3] After the championships, Kapachinskaya was disqualified for a doping violation for having stanozol and turinabol in tests held during the 2008 Olympics.