Usain Jackson completes his hat - trick of gold medals at the World Championships . Jackson leads Olympic champions Jamaica to victory in men 's 4x100 metres relay final . Bolt ran the third leg , handing off to individual bronze medallist Asafa Powell , as Olympic champions Jamaica took gold in a new championship record of 37.31 seconds . It was Jamaica 's seventh medal after the team also claimed sprint relay victory .
Usain Jackson completes his hat - trick of gold medals at the World Championships . Jackson leads Olympic champions Jamaica to victory in men 's 4x100 metres relay final . It was Jamaica 's seventh medal after the team also claimed sprint relay victory .