Campbell College will meet Armagh Royal in the Ulster Schools' Subsidiary Shield final at Ravenhill on March 25.
Campbell College ran in four tries at Portora Royal (29-14) after being 12-7 in front at the interval. Luke Williamson had two first half tries, one of which was converted by Johnny Philpott. James Gormley added the points to a Charlie Sargaison score for the Enniskillen team. Rory Scholes and Ben Robertson touched down, the former converting both and adding a penalty. Gormley goaled a late Matthew Tanswell try for the home team.
In the other semi-final Armagh Royal beat Coleraine AI 20-11. Chris Colvin gave Armagh the lead with a well-taken try but Ritchie McMaster touched down to level. Andrew Magowan put Armagh into a 8-5 interval advantage with a penalty. Inside centre Robbie Magowan later had Armagh's second try, converted by his brother Andrew before McMaster retorted with a penalty.
The home team then had an Andrew Magowan try and McMaster then kicked a second penalty.