St Patrick's breezed to victory over a disappointing, albeit nine-man, Waterford by the Camac.
It was an SSE Airtricity League game in which referee Graham Kelly had a pivotal role, sending off two visiting players – Sander Puri and Gavin Holohan – in somewhat controversial circumstances.
That said, Pat's were denied what could have been a penalty, missed another and were more than worthy of the points, thanks to a Ryan Brennan header.
The Patrick's team was without Owen Garvan, Conan Byrne and Christy Fagan, all on the bench; Waterford soldiered without two influential but suspended foreign players, Bastien Héry and Stanley Aborah.
Another crucial absentee was former Saint Kenny Browne, as he continues to recover from a rib injury.
On 14 minutes, a shocking ball from Brennan found the out-of-sorts Izzy Akinade, who made a mess of his pass and Pat's were let off.
However, Brennan made up for that blunder a minute later when he headed home unmarked from a lovely Darragh Markey cross.
It was a really open first quarter, plenty of space available when both teams attacked on the break and more goals seemed certain.
That seemed even more of a formality on 26 minutes when Keegan was pushed over in the box and had a chance to slot home his spot kick but he was wide of the post.
Frustratingly for Pat's, after the penalty had been awarded, Brennan had blasted the ball into the net – but it wouldn't count.
Barry Murphy rode his luck, fumbling from a corner on 34 minutes and then giving the ball away in a dangerous area.
Dylan Barnett's cross just missed Courtney Duffus on 38 minutes, just before David Webster's superb pass found Akinade, whose control was not ideal and he drilled at Murphy.
Tyson Farago was introduced at the break in nets for Pat's, who were a man as well as a goal up five minutes into the second half when Puri got a second yellow for what was deemed to be a dive.
James Doona's stinging free-kick on 59 minutes forced a fine Vigouroux save.
Brennan missed another glorious chance as Pat's totally dominated midway through the second half, before Lennon's long-range drive was deflected wide of a stranded Vigouroux.
What little hope the Blues had evaporated when Kelly dished out a straight red when Holohan went through Markey.
St Patrick's Athletic: Murphy (Farago 46), Bermingham, Toner, Besmond, Madden, Clarke, Lennon, Markey (Garvan 86), Doona (Byrne 87), Brennan, Keegan.
Waterford: Vigouroux, Comerford, Webster, Feely (Kavanagh 46), Barnett, Kasmi (O'Halloran 70), Keegan, Puri, Holohan, Akinade (Martin 70), Duffus.
Referee: Graham Kelly (Cork).