Carlow reached their only final to date, and opened well, leading Mayo by 0-2 to 0-1 after ten minutes.
But then the 'flying doctor' Pádraig Carney, who came home from America for the game, levelled before Tommy Langan punched a goal from a Carney centre in the 26th minute.
Mayo's second goal from M. Flanagan in the 10th minute of the second-half ended Carlow's dreams of National League glory, and gave Mayo their ninth NFL win.
[1][2][3] Teams are placed into Divisions I, II, III and IV.
Carlow won, ahead of Kerry, Cork, Wexford, Kildare, Waterford and Tipperary.