Philip Lowry's injury-time header secured success for defending champions Crusaders - minutes after a penalty save by Sean O'Neill to prevent Marc Griffin handing Warrenpoint Town a late lead.
The winning goal arrived as two Crues substitutes combined to turn the tables on a day of drama, with Lowry's goal off a Ross Clarke corner-kick with the clock on 92 minutes.
It was the second Crusaders goal of the afternoon in injury-time, with Stephen Baxter's men getting back on level terms in the closing seconds of the first half.
Warrenpoint were handed a golden opportunity to gain a first win of the season - and cap a superb performance - when Michael Ruddy's foul on Simon Kelly resulted in a penalty kick.
However, Griffin could not find a path past O'Neill.
Crusaders - aiming to bounce back from the previous weekend's loss to Linfield - enjoyed the early openings.
A Ruddy cross from the left was met by Rory Patterson's firm header but Berraat Turker proved comfortable to claim.
Jordan Owens, on his second appearance following a return from injury, offered early evidence of his aerial threat to meet Paul Heatley's corner-kick but the effort dropped wide.
Griffin marked his first appearance in Warrenpoint colours with a drive from distance as the hosts' confidence increased.
Heatley forced Turker into a smart stop with Declan Caddell clearing the crossbar off the rebound but Warrenpoint's mix of defensive resolve and attacking intent offered encouragement to the league's basement side.
That encouragement turned to end product on 38 minutes with the opening goal when Eamon Scannell's dangerous delivery was attacked by Ciaran O'Connor and the return ball powered home on his debut from Maxim Kouogun, Warrenpoint's Cameroon-born centre-back signing from UCD.
Crusaders finished a frustrating first half with a flourish to grab an injury-time equaliser off Heatley's corner-kick and a decisive Owens header.
Warrenpoint carved out the first talking point of the second half when player/coach Kelly's header proved too high from another testing Scannell corner-kick.
Owens came close to his second goal, however, with a near-post header but it bounced off the upright.
Alan O'Sullivan created space with a successful turn but O'Neill raced off his line to smother the effort.
Crusaders almost took advantage late on of a misplaced Warrenpoint pass but Heatley's drilled attempt across the face of goal lacked a decisive touch.
However, the closing minutes served up plenty of talking points.
WARRENPOINT TOWN: Turker, Hughes, Reilly, Kelly, Griffin (Moan, 89), O'Sullivan, McCaffrey (Foster, 78), Kouogun, Scannell (Donnelly, 76), O'Connor, Norton.
SUBS (NOT USED): Parr, McGrandles, Lynch, Houston.
CRUSADERS: O'Neill, Burns, McChrystal, Beverland, Caddell, Forsythe (Cushley, 84), Ruddy, J.Owens, Snoddy (Lowry, 57), Heatley, Patterson (Clarke, 63).
SUBS (NOT USED): Doherty, Glackin, Carvill, K.Owens.