Simon McClean stepped off the substitutes’ bench and set Tandragee Rovers on the path to three hard-earned points thanks to a superb solo run in the closing minutes.
St Mary’s produced a spirited performance at Tandragee Road but McClean’s impressive footwork and control led to a late winning goal for Rovers.
Rovers dominated the initial exchanges and grabbed control thanks to Mark Bicker’s quick reactions to convert the rebound after Lee Wells’ initial shot from distance.
Luke Carvill fired over the bar in response but Rovers carved out another opening when Cecil Corbett’s header dropped the wrong side of the post.
A strong finish to the first half kept St Mary’s in contention but the hosts had to wait until after the break to equalise when Sean Brady steered home a Chris Mackle delivery.
A last-gasp tackle by Jamie Rooney prevented St Mary’s Ryan McKee from turning the tables then late pressure produced a winning strike following McClean’s impressive cameo.
Scott Walker, the Rovers manager, expressed post-match disappointment at a failure to build on the bright start but satisfaction due to the determination on display.
“It was very disappointing not to get something,” said St Mary’s Gerry Fay. “We matched up well and it was a much-improved performance compared to previous games against Rovers.
“That made the scoreline all the more disappointing but we have got to take the positives.”
TANDRAGEE ROVERS: Richard McGivern, Philip Pedlow, Jamie Rooney, Colin Bingham, Gary Whiteside, Iain Latimer, Lee Wells, Mark Bicker, Johnny Black, Cecil Corbett, AJ Gallagher. Subs: Simon McClean, Gareth Dobbs, Jamie Uprichard, Scott Walker.