In the 2006 season he ranked number one in the world for the season – South Africa's first black athlete to do so. He was made South African Sportsman of the Year in recognition of this. At the 2006 World Indoor Championships he won a silver medal, and he repeated the feat two years later at the 2008 edition. He represented South Africa at the 2008 Beijing Olympics but was knocked out of the 800 m at the semi-final stage.