Shane Griffin's 92nd-minute screamer condemned Derry City to a desperately disappointing 2-1 defeat by Waterford.
The Candystripes led through Stephen Mallon's 32nd-minute strike before Sam Bone's stunning effort saw Waterford draw level.
With the League of Ireland game heading towards a draw, substitute Griffin struck in the dying seconds.
It is Waterford's first home win of the season, while Derry are still waiting for their first away victory.
The Candystripes were without experienced trio Ciaran Coll, Ally Gilchrist and Gerardo Bruna, but will still be frustrated at what was a very poor display at the Regional Sports Centre.
Having claimed their first win of the season last week against Bohemians, Derry were expected to carry some momentum into their meeting with a Waterford side coming off back-to-back defeats.
However they never found a rhythm in their play and Mallon's opener, a fine near post finish having collected a quick free-kick, was firmly against the run of play.
Waterford looks comfortable the brighter side with Linfield loanee Michael O'Connor causing Derry's defence problems.
The hosts were level after 44 minutes when a corner fell to Bone at the edge of the area, who slammed his shot into the top corner.
A low-key second half looked to be petering out with both sides seemingly content with a point before Waterford rallied late on with Peter Cherrie making a smart save to keep out Akin Odimayo in injury time.
However Waterford would not be denied and with time all but up, Griffin sent a stunning 30-yard effort whistling beyond Cherrie to grab the three points for his side.