Jimmy Carr scored both goals for Jason Purcell's side- the opener coming after less than 20 seconds, while the winner came with twelve minutes left.
St Michaels will be joined in the semi-final draw by the holders Sheriff YC, Collinstown and Ballynanty Rovers, who all won today.
Meanwhile, in results from around the county;
Tipperary Cup: Old Bridge 2-3 Bansha Celtic, Suirside 0-4 Clonmel Town.
TSDL Premier League: Glengoole United 2-2 Clonmel Celtic