In 1952, Kavanagh became the first Australian to win a motorcycle Grand Prix race when he won the 350cc Ulster Grand Prix. In 1956, he won the Junior TT at the Isle of Man TT races. Kavanagh entered two Formula One Grands Prix in 1958 with his own Maserati 250F, firstly in Monaco where he failed to qualify, and lastly in the Belgian Grand Prix where he missed out on the race having blown his engine in practice, after having qualified 20th of 28 entrants.