Waterford paid the penalty as they finished with 10 men against relegated Longford at Bishopsgate to blow the chance of putting their automatic Premier Division survival back into their own hands.
The result means Marc Bircham's Blues remain second bottom of the table and must hope to better Finn Harps’ result in next week’s final round of matches to avoid the promotion/relegation play-off.
St Patrick's Athletic visit the RSC while Harps are at home to Longford.
Waterford conjured the first chance of a first half they shaded in the midlands mist on eight minutes.
Greg Halford nodded down Phoenix Patterson's free kick to Niall O’Keeffe who, perhaps not realising the time and space afford him, sliced his shot wastefully wide.
Much of Waterford’s threat stemmed from the trickery of Phoenix Patterson, the winger having a stinging drive bravely blocked by Joe Manley before delivering a sublime cross which Blues’ leading scorer John Martin headed wide.
Working hard, Longford remained well in the game, Blues' Darragh Power having to defend a dangerous Shane Elworthy cross ahead of Town winning three corners.
Waterford quickly regained the initiative, troubling Longford from a couple of corners of their own on 38 minutes.
Patterson’s ball in wasn’t fully cleared with Shane Griffin’s dink sailing just over the top.
Martin had another sight of goal a minute later when Junior Quitirna’s cross broke kindly for him, but never got hold of his strike which hit defender Elworthy and was cleared for a corner.
Waterford got away with a mistake with scarcely a minute of the second half played when Darragh Nugent intercepted a poor Halford pass to put fellow Shamrock Rovers loanee Dean Williams in on goal.
Williams' hurried shot lacked the power to trouble Brian Murphy as Blues survived.
The Town striker was then hauled down on the halfway line by Power when he looked to have a clear run on goal, though not even a foul was given, much to the midlanders' ire.
The main action resumed in the home area with Lee Steacy saving well with his feet from Eddie Nolan’s drive before Waterford made the breakthrough on 65 minutes.
Rob Manley’s weak near spot header from Halford long throw dropped for Anthony Wordsworth who controlled the ball superbly before spinning and hitting a half volley that arrowed into the roof of the net.
All Waterford’s good work was undone 11 minutes later, though, when Nolan tripped Williams just inside the area.
The stiker beat Murphy to find the net off a post from the resulting penalty to equalise.
In a grandstand finish, Steacy earned Longford their point with the save of the game three minutes later.
Nolan looked to have redeemed himself when getting a firm header to Stafford’s cross only for Steacy to dive full stretch to his right to push the effort round a post.
Waterford will be without Halford for Friday’s final game of the regular season as the big defender was dismissed for a second yellow card offence following a foul on Aodh Dervin six minutes from time.
Longford Town: Lee Steacy; Shane Elworthy, Joe Manley, Aaron O’Driscoll, Paddy Kirk; Aodh Dervin, Aaron Robinson (Callum Warfield 68); Darragh Nugent, Dean Williams, Conor Davis (Aaron McNally 68); Rob Manley.
Waterford: Brian Murphy; Darragh Power, Greg Halford, Eddie Nolan, Jack Stafford; Niall O’Keeffe, Anthony Wordsworth, Shane Griffin (Callum Stringer 73; Kyle Ferguson 78) ; John Martin, Junior Quitirna, Phoenix Patterson.
Referee: Ray Matthews