Seir Kieran recorded their first championship victory over Birr in 19 years at St. Brendan's Park yesterday to set up an Offaly SHC semi-final meeting with St. Rynagh's.
The Clareen men laid the foundations for a sensational 3-17 to 0-15 victory over the four-time All-Ireland club champions in the first half when goals from Adrian Hynes and James Mulrooney helped them to a 2-9 to 0-5 lead at the break.
Paul Cleary had to settle for a point from a Birr penalty before Hynes added his second goal to put the result beyond doubt.
Coolderry are expected to pose a stern test for three-in-a-row chasing Kilcormac/Killoughey in the other semi-final after they swept to a 2-23 to 1-11 victory over Shinrone in yesterday's other quarter-final.
County star Brian Carroll shot 0-13 for Ken Hogan's charges, who look to be coming into form at just the right time.