Dublin City 3 Waterford United 1
Late goals from Philip Hughes and Ray Scully, deep in stoppage time, earned bottom-of-the-table Dublin City a second win of the season.
The crossbars at either end were struck before a lively game was given the gloss of its first goal on 29 minutes. It fell to Dublin with Don Tierney scoring a sublime first goal for the club; finding the top corner of the net with a rising shot.
O'Neill had earlier crashed a close range effort from Keith Foy's cross onto the bar, something Dublin's Jason Colwell did at the other end as he cleared off his own line from a Daryl Murphy header.
Waterford equalised on 72 minutes when Dublin keeper Robbie Horgan only succeeded in pushing a Pat Purcell shot onto a post and Vinny Sullivan scooped in the rebound.
Mark Clifford was then sent off a minute later for a second booking, before Waterford's night really toured sour with Dublin regaining the lead within a further two minutes when O'Neill crossed for striker partner Hughes to head home. Substitute Scully hit a stunning third six minutes into stoppage time.
DUBLIN CITY:Horgan; Burke, Whelehan, Byrne, Foy; C O'Connor, Colwell, Tierney, Brennan (Scully, 90 mins); O'Neill (Collins, 87 mins), Hughes (Ennis, 87 mins).
WATERFORD UNITED:Connor; Mulcahy, Breen, Purcell, Frost; Kennedy (O'Brien, 66 mins, Banville 90 mins), Reynolds (Carey, 66 mins), Clifford, Waters; Sullivan, Murphy.
Referee:D Hanney (Dublin).