Waterpark moved to 6th in Division Two of the Munster Junior League at the weekend, beating Clare's St Senans RFC at Ballinakill.
It marks a second win in three games for the city club, who 18-14 to the good by the full-time whistle on Sunday.
Waterpark were up 10-nil at half time, with centre Ryan Jackson dotting down and out half Willie Walsh kicking a conversion and a penalty.
They would extend their lead midway through the second half when winger Gary Walsh found the whitewash. Walsh missed the ensuing conversion but slotted a penalty to extend their lead. The visitors responded with two converted scores, but it wasn't enough to reel in the hosts.
Elsewhere, Dungarvan were left to lick their wounds following defeat to Carrick On Suir.
The West Waterford club were missing six of their starters ahead of kick-off, but a well-drilled Carrick side were full value for their win.
It ended 37-21 in favour of the visitors despite Dungarvan leading 21-14 at the break. Shane Norris, Alan McMahon and Ricky Lopez dotted down with Dave Hockey converting all three.
The game hinged on the first five minutes of the second half. Carrick were down to 13 men and with space out wide Dungarvan chip kicked into 22 to allow a mark, from that Carrick broke up the field and scored bringing it back to 21-21.
With the wind now behind them, they played well and controlled the game for the remainder to add 16 more points on the board.
The result leaves Dungarvan fifth in the Division Three standings, with Carrick closing the gap to two points in seventh.
Waterford City meanwhile were not playing this past weekend. They are second bottom in the table, and still in search of their first win.
They're back on the pitch this Sunday when they host Rugbaí Chorca Dhuibhne RFC, Waterpark travel to Cobh Pirates, while Dungarvan make the trip to face Ardscoil Old Boys in Limerick.
