Rio de Janeiro (AFP) - South African Wayde Van Niekerk smashed Michael Johnson's long-standing 400m record when he stormed to Olympic gold.
Van Niekerk, running in the unfavoured lane eight, blasted off the final corner to time 43.03sec, 0.15sec quicker than Johnson's previous world best set in Seville in 1999.
Defending champion Kirani James of Grenada took silver in 43.76sec, with American Lashawn Merritt bronze (43.85).