Leading by 22-10 at half-time the Offaly side showed the form that sees them top of Division 1A in the Leinster League, to put Monivea away with a strong running performance.
Elsewhere Kanturk caused the upset of the round by beating Cooke 32-23. Trailing by six points at half-time the Cork club ran in two second half tries from Arran Jones and Luke McCabe. Two conversions and a penalty from Darragh Meade sealed the win.
Another Leinster League side, Enniscorthy, will also be in the semi-finals thanks to a 15-8 victory over Donaghadee at Ross Road.
The fourth semi-final spot belongs to Clogher Valley who beat Newbridge 7-5 in a tight affair at the Cran.
The draw for the semi-finals took place in the IRFU offices today and following the weekend results, holders Tullamore have been pitted against Kanturk.
Clogher Valley have earned themselves a home semi-final against Enniscorthy. The semi-final matches are to be played on Saturday, January 26, 2013 (kick-ooff 2.30pm).
ULSTER BANK ALL-IRELAND JUNIOR CUP SEMI-FINALS:
Clogher Valley v Enniscorthy, the Cran
Kanturk v Tullamore, Knocknacolon