And for the second time this season it was Tom Elmes who heaped the misery on Harps.
Harps looked to have sealed all three points after coming back from 2-0 down before Shaun McGowan made it 3-2 with four minutes remaining.
Goals from Shane Nolan and Joe Mulcahy gave Wexford the perfect start and putting Wexford well on their way to recording a third straight league win over Harps this season.
However, Peter Hutton’s side rallied superbly and header from Thomas McMonagle brought the home side back into the contest before skipper Kevin McHugh rifled home a thunderous long-range free-kick early in the second half.
With the game still up for grabs and both side’s pushing hard, Harps appeared to have struck the final blow when McGowan burst forward to slam home with four minutes remaining.
Wexford, though, utilised every second of the referee’s four minutes added on time as Elmes cut inside from the left before unleashing an ambitious shot that took a wicked deflection off a Harps player before looping over the head of goalkeeper Ciaran Gallagher.
Elmes scored the winner the last time the sides met in Ballybofey and his goal this time around was enough to keep Harps below Wexford in the First Division standings.