Kilkenny dethroned Leinster U21 HC champions Dublin with a 0-21 to 0-16 victory at Nowlan Park on Wednesday evening.
Eddie Brennan's charges were stunned by Westmeath 12 months ago, but the Cats looked sharp and hungry as they marched into the semis.
Alan Murphy helped the hosts to 0-09 to 0-07 half-time lead, and with the breeze on their backs on the turnaround, Kilkenny kicked on.
Murphy finished with a haul of 0-08 in an impressive five-point win that sets up a last-four collision - and a shot at revenge - against Westmeath.
They produced a storming comeback to eventually see off Laois 1-20 to 0-21 after extra-time.
The Lake County were six points down with seven minutes to g and on the ropes, but a Ciaran Doyle goal a score at the death from Darragh Clinton kept them in it.
It was nip and tuck thereafter but Westmeath found enough to prevail in Mullingar.
Wexford had little trouble in swatting Offaly aside, strolling to a 4-21 to 2-9 success at Wexford Park.
Stephen O’Gorman, Cathal Dunbar and Darragh Pepper all goaled in the second half to earn a meeting with Carlow, who had too much for Kildare in a 1-21 to 2-14 Newbridge victory.
Leinster U21 HC results:
Kilkenny 0-21 Dublin 0-16
Westmeath 1-20 Laois 0-21
Kildare 2-14 Carlow 1-21
Wexford 4-21 Offaly 2-9
