After remaining undefeated throughout the first year of his career (16 wins and 1 draw), Leahy suffered his first loss on 28 October 1957 in Birmingham, where he was knocked out in one round by Tommy Tagoe.

On 23 February 1961 Leahy unsuccessfully challenged the Welshman Brian Curvis for the British and Commonwealth Welterweight titles, he was knocked out in the eighth round.

[1] Leahy then went on to beat Gil Diaz in Birmingham and launched an unsuccessful challenge for the Commonwealth Middleweight title against Gomeo Brennan in London.

There were two further losses to Tuna Scanlan and Dante Pelaez (controversially stopped due to a cut over Leahy's right eye); plus a unanimous decision victory in Boston over Larry Carney.

Although Robinson at this point was considered past his best, he had the support of the Scottish crowd behind him, and managed to trouble the much younger Leahy with his handspeed and volume of punches.

In his next fight Leahy attempted to defend his British middleweight crown for the first time, however, he once again lost a 15-round decision, enabling Wally Swift to become the new champion.

[3] In 2003 Leahy was on a family trip to New York with his wife Teresa; sister-in-law Eileen and eldest son, Noel; when it became apparent that his memory was failing.