Duggan first came to prominence on the inter-county scene when he made his debut in a 7-0 to 6-2 All-Ireland semi-final defeat by Antrim in 1943.
Duggan played his club hurling with his local Liam Mellows club and enjoyed some success. He won back-to-back county titles with the club in 1945 and 1946.
Duggan also lined out with Connacht in the inter-provincial hurling competition. He won his sole Railway Cup medal in 1947 as his side defeated Munster.
In 1951 Galway made a long-overdue breakthrough on the national scene. A 6-7 to 3-4 defeat of Wexford secured victory in the "home" National Hurling League final. A narrow 2-11 to 2-8 defeat of New York in the actual league final gave Duggan a National League medal.
Two years later in 1953 Galway defeated a star-studded Kilkenny team in the penultimate stage of the championship. This victory allowed Duggan's side to advance to the All-Ireland final where Cork provided the opposition. The game itself is remembered as one of the ugliest championship deciders ever and is clouded in controversy due to the injury to the Galway captain, Mick Burke. Galway lost the game by 3-3 to 0-8. After the match at the Gresham Hotel in Dublin a fight broke out when another Galway player struck Cork's Christy Ring. The following morning another fight broke out when another member of the Galway panel attempted to hit Ring. The fights, however, ended just as quickly as they had started. This defeat brought the curtain down on Duggan's inter-county career.
