Sligo Rovers 1 Waterford United 2
Dave Mulcahy scored a terrific winner to give Waterford 's season a huge lift in their bid to avoid relegation.
The win sees Blues regain their five-point lead over bottom-of-the-table Longford Town and move to within a point of third-bottom Galway United whom they meet at home in their second last match.
Waterford were good value for their lead when it arrived on 32 minutes.
It came about from a well-worked free-kick with Dave Warren putting Ray Scully away down the right and his cross was powerfully headed home by Vinny Sullivan for his seventh goal of the season.
Sullivan blazed over the bar while another of his efforts was blocked by a defender before a mistake gifted Sligo their equaliser three minutes before the break.
Blues' defender David Breen failed to clear an innocent looking ball down the middle and Fahrudin Kuduzovic punished the error to drill a shot past Dean Delaney from 16 yards.
Blues regained the lead on 61 minutes when Mulcahy powered his way into the Sligo box from Sullivan's flick, took a touch and blasted the ball to the net.
Sligo had defender Danny Ventre very harshly sent off three minutes later for a foul on Willy John Kiely, scarcely a straight red card from referee Richie Winter.