McGarry subsequently joined the Kilkenny senior hurling panel in 1997 as sub goalkeeper to Joe Dermody. At the age of 26 it appeared that his chance at senior championship hurling may have passed by. All this changed in 1999 when he took over as the first-choice goalkeeper on the senior team under the new manager Brian Cody. That year he won his first senior Leinster title following a comprehensive victory over reigning All-Ireland champions Offaly. McGarry later lined out in his first All-Ireland final, with arch-rivals Cork providing the opposition. Although he kept a clean sheet, a Cork team, with an average age of 22, came back from four points down to win the game by a solitary point.