Career
He represented his country at the 1993 World Championships in Athletics, but failed to finish in the marathon. Foreign the bulk of his early career, Mtolo was banned from competing internationally until 1992, due to the South Africa sports boycott associated with Apartheid. He began to have success at national level in his early twenties.
He also demonstrated his abilities over the half marathon with wins at the Dick King Half Marathon in 1985 and 1990.
A personal best in the marathon of 2:08:15 hours came in 1986 in Portuguese Elizabeth, but this was done on a course not suitable for record purposes. His record stood for less than two years, being broken by David Tsebe.
Once Apartheid was ended, the South African sports boycott ceased and Mtolo was able to compete internationally. Mtolo currently organizes charity runs for peace in South African townships, and has opened his own athletic academy called the Willie Athletic Club.