2–10 to 0–12 defeat of Dublin in the provincial decider gave him his first Leinster medal in that grade. Shefflin won a second Leinster medal in 1999, following a 1–17 to 1–6 trouncing of Offaly. The subsequent All-Ireland decider was a thrilling affair, with Kilkenny securing a narrow 1–13 to 0–14 defeat of Galway to give Shefflin his sole All-Ireland medal. Senior Unsuccessful beginning Shefflin made his senior competitive debut for Kilkenny on 21 February 1999 in a 0–14 to 1–9 league defeat by Cork. That campaign ended at the semi-final stage, however, Shefflin retained his place on the starting fifteen for the subsequent championship, making his provincial debut in a 6–21 to 1–14 semi-final trouncing of Laois. Kilkenny later faced Offaly in the provincial final. A huge 5–14 to 1–16 victory over their near rivals and reigning All-Ireland champions gave Kilkenny the win and gave Shefflin a first Leinster medal. The subsequent All-Ireland decider saw Kilkenny face Cork on 12 September 1999. In a dour contest played on a wet day, Cork trailed by 0–5 to 0–4 after a low-scoring first half. Kilkenny increased the pace after the interval, pulling into a four-point lead. Cork moved up a gear and through Joe Deane, Ben O'Connor and Seánie McGrath Cork scored five unanswered points. Kilkenny could only manage one more score – a point from a Shefflin free – and Cork held out to win by 0–13 to 0–12. Early successes In 2000, Shefflin won a second successive Leinster medal following another comfortable 2–21 to 1–13 victory over Offaly. As a result of the so-called "back-door" system both sides later faced off against each other again in the All-Ireland final on 10 September 2000. D.J. Carey capitalised on an Offaly mistake after just six minutes to start a goal-fest for 'the Cats'. Carey scored 2–4 in all, sharing his second goal with Shefflin who also scored a goal in the second-half. At the full-time whistle Kilkenny were the champions by 5–15 to 1–14 and Shefflin collected his first All-Ireland medal. He was subsequently honoured with his first All-Star award. Kilkenny's provincial dominance continued in 2001 and a powerful 2–19 to 0–12 defeat of Wexford gave Shefflin a third Leinster medal. Kilkenny bounced back in 2002. Shefflin won his first National Hurling League medal, as a late Brian Dowling free secured a narrow 2–15 to 2–14 victory over Cork. He later