Neal Fenn suffered the second defeat of his Cork City reign as manager as they were beaten by Waterford in the Munster Derby at Turner's Cross.
Daire O’Connor had given City the lead in the first half but goals in the closing stages from Maxim Kouogun and Walter Figueira was enough to earn Waterford the three points which means Cork are still without a home win since the 10 May.
Fenn made four changes to his side following their disappointing 4-2 defeat to Sligo Rovers in his first game in charge of the club last Friday night.
The new City boss made a big call in goal as he decided to drop veteran goalkeeper Mark McNulty and replaced him with Tadgh Ryan, who was making his competitive debut.
The 22-year-old shot-stopper was almost beaten inside four minutes though when former Cork players John Kavanagh and Shane Duggan combined in the penalty area but the latter rolled the ball narrowly wide of the bottom left corner.
The home side first threatened with 12 minutes on the clock but defender Dan Casey, who scored in the defeat to Sligo, could only send his header over the bar from close range.
Alan Reynolds made three alterations to his side that drew 1-1 with Derry City in their last outing – Rory Feely, Jonathan Lunney and Dean O'Halloran coming in for Maxim Kouogun and Zak Elbouzedi - and they twice went close to taking the lead as the half progressed.
Shortly after Dean O’Halloran saw his shot from a good position deflect just past the near post, Walter Figueira’s angled drive was brilliantly tipped wide of the bottom left corner by the outstretched Tadgh Ryan.
They would be punished for not taking those chances as City took the lead midway through the first half thanks to a stunning strike from Daire O’Connor.
The winger collected Shane Griffin’s quick short corner but getting the ball on to his right foot and bending it against the underside of the crossbar and into the far bottom right corner.
City was now full of confidence but they didn’t truly threaten their opposition’s goal until the beginning of the second period.
Mark O’Sullivan had now great chances to score with his header in quick succession but on both occasions, he was denied by Waterford’s net-minder Matthew Connor.
Connor nearly let Karl Sheppard’s cross from the right squirm over his own line on 66 but he made amends minutes later when he produced another fine stop to deny Eoghan Stokes.
While Waterford only trailed 1-0 they still had hope and with eight minutes remaining, they equalised when substitute Maxim Kouogun planted his free header past Ryan from a few yards.
City piled forward in search of a winner and they left themselves opened at the back which Waterford took full advantage of in injury time as they grabbed the decisive goal.
Michael O’Connor’s pass released George Poynton and he unselfishly teed up Walter Figueira to fire home to give the blues an unlikely three points.
Cork City: Tadgh Ryan; Josh Honohan, Conor McCarthy, Dan Casey, Shane Griffin; Garry Buckley, Conor McCormack; Karl Sheppard, Eoghan Stokes, Daire O’Connor (Darragh Crowley 54); Mark O’Sullivan (Beineon O’Brien-Whitmarsh 82).
Waterford: Matthew Connor; John Kavanagh (Maxim Kouogun 19), Rory Feely, Kenny Browne, Kevin Lynch; Sam Bone (Michael O’Connor ht), Jonathan Lunney, Shane Duggan, Georgie Poynton; Dean O'Halloran (Cory Galvin 58), Walter Figueira.
Referee: Paul McLaughlin.