During the 1957-58 National League, Larkin was drafted onto the Tipperary senior hurling team. He made his Munster Championship debut on 1 June 1958 when he was introduced as a substitute for John Haugh in a 2-10 to 1-05 defeat of Limerick. On 6 July 1958, Larkin won a Munster Championship medal after lining out at centre-forward in Tipperary's 4-12 to 1-05 victory over Waterford in the final. After illness rule him out of a starting fifteen place for the All-Ireland semi-final, he was back at centre-forward for the All-Ireland final against Galway on 7 September 1958. Larkin scored two points from play and ended the game with an All-Ireland medal after the 4-09 to 2-05 victory.[citation needed]
On 3 May 1959, Larkin was selected at right corner-forward when Tipperary qualified to play Waterford in the National League final. He was held scoreless throughout but ended the game with a winners' medal after the 0-15 to 0-07 victory. Larkin was dropped from the panel after the Munster Championship.[citation needed]
