Career
In April 1965 Van Zyl reached the final of the British Hard Court Championships at Bournemouth but was beaten in straight sets by Ann Haydon-Jones. She reached the semi finals of the French Open singles in 1967, beating Billie Jean King in the quarter final before losing to Lesley Turner Bowrey. Van Zyl reached the final of the South African Championships singles event on three occasions, winning the title in 1963 and 1975 and ending as runner–up in 1965.
According to A. Wallis Myers of the Daily Telegraph and the Daily Mail, Van Zyl was ranked in the world top ten in 1965, 1966, and 1968, reaching a career high of World Number.
6 in those rankings in 1965 and 1966. Singles 8 (6 titles – 2 runner-ups)
Doubles 7 (4 titles, 3 runner-ups)
Mixed doubles 1.