Laois ousted last years beaten All-Ireland finalists Dublin, while Wexford also advanced to a Leinster semi-final berth.
A late point for Sean Curran also secured victory for Tipperary over Cork in the Bord Gais Energy Munster Under 21 Hurling Championship tonight.
At O'Moore Park, Portlaoise the hosts dug deep in the final quarter to carve out a 2-15 to 0-17 win over Dublin.
The visitors led for the bulk of this contest, but John Henderson's charges failed to stick to the script in the final quarter as Laois showed great character to take a late lead and hold out for victory.
It was Senior player Neil Foyle who claimed a vital point late on for Laois, with the full-forward also registering his sides first goal in the 42nd minute to cut the gap to a point at that stage.
Earlier, Dublin lead by 0-10 to 0-8 at the break, but would rue four first quarter wides and some other missed chances, with Laois offering a strong defensive display throughout.
Five of Dublin's forwards were on target in that opening half, with John Hetherton, Mark Schutte, Eamon Dillon, Sean McGrath and Thomas Connelly along with midfielder Stephen O'Connor taking scores.
Laois kept in touch through Senior players Stephen Maher and Willie Dunphy, while captain Darren King also claimed a first-half point.
Dublin moved four points clear inside 11 minutes of the restart, but Laois mounted a comeback.
Foyle's goal cut the gap to the minimum, but it wasn't until substitute Ross King registered a point in the 51st minute that Laois took the lead for the first time.
Dublin battled hard thanks to the efforts of Sean McGrath and although the Kilmacud Crokes clubman forced a draw on two occasions in the closing six minutes, there was still time for a Laois comeback.
Foyle's lone point of the hour pushed Laois ahead on the stroke of 60 minutes, before a late Brendan Reddin goal confirmed a semi-final berth against Carlow.
Wexford are also through to a Leinster semi-final, after recording a comofortable 1-19 to 0-10 win over Offaly at O'Connor Park, Tullamore.
The visitors led by 0-9 to 0-5 at half-time, with Jack Guiney claiming four first half points for Wexford.
Tony Dempsey's charges continued to impress in the second-half leading by 0-18 to 0-10 late on, before Aidan Nolan netted the lone goal of the contest, after a pass from Shane O'Hanlon to seal the contest.
In Munster, Tipperary came from behind to record a slender 0-18 to 0-17 win over Cork at Pairc Ui Chaoimh.
Sean Curran claimed the match winning score in a contest which was tight throughout.
Jamie Coughlan was to the fore for the Rebels with nine points, including a late effort to push Cork 0-17 to 0-15 ahead in the 56th minute.
However, Tipperary finished strongly as scores from David Collins, John O'Dwyer and Curran helped the Premier County to a last-four clash with Limerick on July 17th.