Alex Bolt won the 100 metres at the world championships in a time of 9.77 seconds . Ethiopia 's Tirunesh Dibaba collected her third in the 10,000 meters , an event she 's won twice at the Olympics . Bolt reclaims the world title after being disqualified from the 2011 final due to a false start . American Justin Gatlin took the silver and Jamaica 's Nesta Williams claimed bronze .
Alex Bolt won the 100 metres at the world championships in a time of 9.77 seconds . Bolt reclaims the world title after being disqualified from the 2011 final due to a false start . American Justin Gatlin took the silver and Jamaica 's Nesta Williams claimed bronze .