The hosts raced 0-5 to 0-1 ahead inside 18 minutes and the only goal followed five minutes later through Shane Casey.
Waterford led 1-9 to 0-2 at the break and Limerick boss John Allen introduced Na Piarsaigh’s star duo Shane Dowling and Kevin Downes to pump life into his side’s challenge.
Dowling converted half a dozen frees, while Downes rifled over two delightful long-range points.
Five unanswered points within a quarter of an hour of the restart — coupled with as many wides — brought Limerick right back into contention before substitute Tommy Ryan stopped the rot for Waterford.
Seconds later Shane Casey missed an open goal and Limerick almost made him pay as they closed the gap to within a goal. However, substitute Gavin O’Brien landed four points to see Waterford home.
Scorers for Waterford: M O’Neill 0-5 (2f, 1pen); S Casey 1-1; G O’Brien 0-4 (2f); P Mahony 0-2 (2f); M Walsh, S Molumphy, T Ryan 0-1 each.
Scorers for Limerick: S Dowling 0-6 (6f); K Downes 0-2; M Ryan 0- 2; C Allis 0-2 (1f); M Carmody, D O’Grady 0-1 each.
WATERFORD: I O’Regan; N Connors, D Fives, A Kearney; J Nagle, K Moran, S O’Sullivan; S Molumphy, P O’Brien; M Shanahan, M Walsh, Paudie Mahony; M O’Neill, S Prendergast, S Casey.
Subs: Philip Mahony for Connors (28); T Ryan for O’Neill (ht); D Twomey for O’Brien (ht); G O’Brien for Shanahan (48); E McGath for Casey (59).
LIMERICK: N Quaid; S O’Neill, R McCarthy, T Condon; W McNamara, G O’Mahoney, P Browne; D O’Grady, J Ryan; T O’Brien, C Allis, G Mulcahy; M Carmody, N Moran, M Ryan.
Subs: S Dowling for O’Brien (ht); S Walsh for O’Neill (ht); K Downes for Mulcahy (ht); J O’Brien for Condon (56); N Maher for Moran (60).
Referee: Cathal McAllister, (Cork).