This game was switched from Golden to Thurles venue Dr Morris Park and while heavy pre-match rain made ground conditions difficult, both sides served up an entertaining encounter.
Blackwater trailed by just a point at half-time, 0-8 to 0-9, but raised just one white flag after the break as the Tipperary boys upped the tempo.
Cousins Liam and John McGrath contributed 10 points between them as free-taker Liam led the way with seven while another cousin, Toss, was superb at corner back.
John, brother of Tipp senior star Noel, worked extremely hard throughout and three points from play capped an outstanding display.
Templemore, who shot 0-21 against Doon in their opening match, were denied goals again although centre back Dan McCormack blazed just over the crossbar from a penalty with six minutes remaining. The sides were level four times in the first half but Templemore outscored Blackwater by 0-8 to 0-1 in the second half to secure a crucial win.
Scorers for Templemore CBS: L McGrath 0-7 (6f), J McGrath 0-3, S Hassett 0-2, D McCormack 0-2 (1 pen, 1f), MJ Carroll, T Meade & B Harkin 0-1 each.
Scorers for Blackwater CS: P Prendergast 0-4f, E Sheehan 0-3, P O’Keeffe and F Murray (f) 0-1 each.
TEMPLEMORE CBS: M Kelly; J Keane, D Dunne, T McGrath; K Kennedy, D McCormack, B Bergin; L Treacy, MJ Carroll; J Bergin, S Hassett, L McGrath; T Meade, B Harkin, J McGrath.
BLACKWATER CS: D Curran; R McLoughlin, D Cahallane, S Roche; S Heaphy, D Fives, T O’Brien; F Murray, PJ Curran; S Ryan, P Prendergast, R Barry; A Pratt, E Sheehan, P O’Keeffe.
Sub: D O’Brien for Ryan (55).
Referee: Shane Hourigan (Rathkeale).