After dealing with Donaghadee and Academy in earlier rounds, Rainey 4ths were confident of claiming the scalp of Letterkenny 2nds when they met in the quarter-final of the McCambley Cup at Hatrick Park.
Rainey took their chances and defended stoutly when they had to, progressing to the next stage on a 17-0 scoreline.
Rainey were able to bring in the experienced James McGoldrick and Fintan Martin which allowed them to make a couple of positional switches and they were well on the way with two tries in the first 15 minutes.
Scrum-half Devlin broke loose for the opener and busy hooker McCullagh charged down a kick to score the second at the posts.
Letterkenny then pressed for a spell and missed a kick at goal leaving Rainey 12-0 up at the interval.
Rainey took a major step towards a semi-final place when they moved a tap penalty and No.8 Miller burrowed his way over from a ruck. Devlin converted.
Rainey remained in control and held out well when the Donegal side staged a late rally. They will face much stiffer opposition in the semi-final when they travel to Cookstown.
Saturday’s fixtures: 1st XV v Banbridge (UBL) home, 2.30pm; 3rd XV v Portadown 2nds (away); 4th XV v Portadown 5ths (away).