ST Kilian's DSD are just one win away from their third Leinster Senior B Boys final in four years after a huge victory.
The 2013 winners stunned last year's champions - and All-Ireland finalists - St Tiernan's CS in the quarter-finals last week.
Ballaly school Tiernan's actually beat their Dublin southside neighbours on the way to provincial glory last year, making the victory even sweeter for Kilian's.
Runners-up in 2012, the German school are now on the cusp of another final after Jessie Kamm (2) and Dillon Fox sealed the win. Dean McCormack did his best to keep the holders in the competition, but his brace would prove to be a mere consolation.
Another side into the semi-finals are Scoil Aireagail, Ballyhale, after their quarter-final defeat to James' Street CBS was reversed.
Despite winning the game 1-0, James' were rocked when the result was given to the Kilkenny school because of a player elligability matter.
The other two semi-final places have been filled by Dublin schools.
New Cross College (formerly known as Patrician College) saw off St Fintina's of Enfield in the quarter-finals, while Trinity CS, Ballymun also advanced.
The draw for the semi-final line-ups will be made by FAI Schools in the New Year, with Kilian's undoubtedly the side the rest want to avoid.