In 1977 Mac Curtain made his debut with the Cork senior hurling team. That year he came on as a substitute to win his first senior Munster title. This was later converted into his first senior All-Ireland medal following a win over Wexford in the final. In 1978 Mac Curtain repeated these victories with Cork by capturing his second Munster and All-Ireland titles. 1979 saw Mac Curtain win a third Munster medal, however, Cork were defeated by Galway in the All-Ireland semi-final. In 1980 and 1981 Cork relinquished their Munster titles, however, Mac Curtain won back-to-back National Hurling League medals with his native-county. In 1982 Cork were back and Mac Curtain won his fourth provincial medal. Unfortunately, his side were later defeated by Kilkenny in the All-Ireland final. 1983 saw Mac Curtain win a fifth Munster medal, however, Kilkenny defeated Cork again in the All-Ireland final.