Moon was largely self-taught and practised his skills playing against family in Cabooltura where his father had a dairy farm. Moon enlisted in the Australian Army on 17 March 1942 and reached the rank of corporal. He was discharged on 12 November 1945.
Doubles Runners-up (3).
He also won the 1932 Men"s Doubles title with Jack Crawford. He won all three Men"s titles at the Australian Championships. Moon won his first national title at the 1929 Open when he teamed up with Daphne Akhurst to win the Mixed Doubles championship. In 1934, he won the Mixed Doubles title for a second time with partner Joan Hartigan. In 1930, Moon won the Australian Open Men"s Singles championship defeating Harry Hopman in the final 6–3, 6–1, 6–3. He played in two Davis Cup ties for the Australia Davis Cup team in 1930, against Switzerland and Ireland, and won all four of his singles matches.
