Antrim champions St Gall's made it through to their second Ulster Club final in three seasons, but they almost kicked themselves out of it at Omagh.
They were vastly superior to a hesitant Glenullin, but hit 19 wides over the hour to effectively keep the Derry men in the game right up to the dying moments.
With the wind in their backs, St Gall's quickly established a tried and trusted pattern, with men in support and a swarm defence when not in possession.
Karl Stewart, not for the first time, broke clear of Eunan O'Kane to send his shot zipping just wide at the far post. Stewart added to Terry O'Neill's early point, and a couple from Kevin Niblock had the St Gall's faithful in fine voice, with Ruairi Boylan striking a free between the posts at the other end.
Another Glenullin point from a placed ball from Paddy Bradley left just two points between the sides, and the Allstar full forward's second point had the Oak Leafers very much in touch with five minutes to play in the half.
But St Gall's got as many as 12 men inside their own 20 metre line to squeezed the Bradley brothers out, and on the breakaway, added two more points, both long range gems from midfielder Mark McCrory.
On the stroke of half-time, however, they were reduced to 14 men, midfielder Sean Burke picking up a second yellow card, but went in at the break with a 0-7 to 0-3 advantage.
Numerical parity was restored within 10 seconds of the restart when Glenullin midfielder Ruairi Boylan received straight red card for a high challenge on Sean Kelly.
It was Kelly who ran the show at the heart of the St Gall's defence, even during their most difficult period, midway through the second half, when the Derry champions enjoyed their best spell, hitting four points on the trot.
Two from Paddy Bradley, one from Damien Hasson and a superb effort from Eoin Bradley brought the deficit down to two points.
But, having gone 22 minutes without scoring, the city side rediscovered their finishing touch, late points from Conor McGourty and defender Anto Healy carrying them through to the decider.