Double amputee Oscar Pistorius's historic Olympic campaign ended on Thursday as the South African team failed to complete their 4x400m relay heat.
Ofentse Mogwane fell on the final bend of the second leg as Pistorius, the first double amputee to compete in Olympic athletics, waited to take the baton.
Mogwane had moved up to fifth on the leg but rounding the bend into the final stretch he made contact with Kenyan Vincent Killu and both came to grief.
Pistorius put his hands to his head, walked to the side of the track and sank to his knees staring down the straight. Mogwane received medical attention and left clutching his shoulder.