Usain Bolt wins men 's 200m gold to complete historic sprint double . Score: 6 ` I did n't get a world record -- I really wanted to do it in the 200m -- Rudisha takes gold in one minute 40.91 seconds . Caster Semenya qualifies fastest for women 's 800m final .
Usain Bolt wins men 's 200m gold to complete historic sprint double . Score: 6 Rudisha takes gold in one minute 40.91 seconds . Caster Semenya qualifies fastest for women 's 800m final .