Usain Bolt’s quest to become an athletics legend took a stunning blow today when the triple Olympic champion was disqualified from the 100 metres final at the World Championships for a false start.

European 100metres champion Dwain Chambers opened his 2003 season with a third place in the Modesto Relays in California.

Dwain Chambers and Christian Malcolm have both targeted medals in the 200 metres after seeing Maurice Greene confirm his status as the world's greatest sprinter.