Widely considered the greatest African boxer ever, he was a three-time world champion in two different weight classes.
He won a gold medal as an amateur at the 1978 Commonwealth Games and went 50-2 overall as an amateur.
His longtime trainer was killed in a car accident in 1998, and Nelson never won another fight afterwards.
His wife died from cancer in the 1990s.
He lost a fight with lifelong rival Jeff Fenech in June, 2008.