By this stage Barry-Murphy had joined the Cork senior football team. He was just eighteen years old when he made his senior championship debut in 1973. It was a successful year for the young player as he won his first Munster winners' medal following a 5–12 to 1–15 thrashing of arch-rivals Kerry. Barry-Murphy later lined out with Cork in an All-Ireland final against Galway and proved to be one of the stars of the game, scoring the first of his two goals after just two minutes. One of these goals, where he receives a pass, cheekily solos the ball and waits to pick a spot in the net was chosen as one of RTÉ's Top 20 GAA Moments in 2005. Cork eventually defeated Galway by 3–17 to 2–13 and Barry-Murphy collected an All-Ireland winners' medal.