Olympic champion disqualified in 400m

DAEGU, South Korea -- Olympic champion Christine Ohuruogu of Britain has been disqualified from the women's 400 meters at the world championships after a false start.

Ohuruogu, the 400 winner in the 2007 worlds and 2008 Beijing Olympics, jumped the gun in Heat 3 and was led off the track Saturday at Daegu Stadium.

Ohuruogu has been struggling this season, and even said she thought about skipping the meet in order to concentrate on defending her Olympic title next year in London.

Three weeks ago at Crystal Palace, Ohuruogu finished last.

American teammates Allyson Felix and Sanya Richards-Ross qualified for the semifinals Sunday -- Felix with effortless grace and Richards-Ross putting in her big push in the final stretch to beat Jamaican rival Shericka Williams..

Felix, a three-time world champion in the 200, is looking to double in Daegu.