In 1950, de Gruchy represented Australia at the British Empire Games in Auckland, where he won a silver medal in the 100 yard sprint and was a member of the gold medal-winning 4 × 110 yards relay team.[2]
De Gruchy won the national 100 yard sprint title for the only time in 1951, edging three-time champion John Treloar.[3] He was overlooked in favour of John Treloar for the 1952 Helsinki Olympics.[4]
At the 1952 WA state championships, de Gruchy ran the 100 yard sprint in a wind assisted 9.6 seconds.[5]