Albert Foundry ended 66 years of hurt by booking their place in the Steel & Sons Cup final on Friday night.
The Amateur League club will contest the Christmas showpiece for the first time since 1949 following a remarkable 4-3 victory over PSNI at Seaview.
They raced into a 3-0 lead, before three goals in 19 incredible second-half minutes saw Championship Two side PSNI draw level.
However, all that counted for nothing when Darren McCombe grabbed an 87th-minute winner to send the Paisley Park club into the Christmas morning final where they will play either Crusaders Reserves or Harland & Wolff Welders.
Albert Foundry took an early lead in the fourth minute when Paul Young coolly slotted home.
They grabbed a second just before half-time when an in-swinging corner from Paul Young was nodded home from less than a yard by defender John Burns.
Young added a third five minutes after the break, but the PSNI’s comeback started in the 54th minute when Andrew Blackledge scored, and then Mark Anderson made it 3-2 with a superb 30-yard effort.
Referee Shane Andrews awarded PSNI a penalty in the 73rd minute after Graeme Beck conceded a foul.
Ryan Berry scored from the spot to level the scores.
All the PSNI’s good work was undone in the 87th minute when defender Ashton McDermott missed a header, allowing McCombe to nip in and score an unlikely winner.
Albert Foundry: Cairnduff; Corry, Burns, Moore, McAlinden (43 Beck); D. McCombe, Harris. Maxwell, West; Young, Mitchell (70 McCord)
Subs Not Used: Sloan, Beattie, W. McCombe
PSNI: Harrison, Blair, McDermott, McCrory, Blackledge; Anderson, Hutchinson, Berry, McWilliams, Moody, Adamczyk
Subs Not Used: Adams, Manly, McLaughlin, McCullough, Simms