Both sides traded points in the opening quarter but a Shane Curtin white flag in the 16th minute pushed Na Piarsaigh into a three-point lead.
The Rockies had a good period of possession and levelled proceedings in the 29th minute when Kevin O’Keeffe punished rare sloppy Na Piarsaigh defending with a magnificent goal.
Keith Buckley had the final say of the half when he drilled over a long-range point that gave Na Piarsaigh a slender 0-11 to 1-7 lead at the break.
The Rockies looked a far slicker outfit on the restart and three unanswered points from free taker Kevin O’Keeffe was followed by a stunning Eoin O’Mara goal.
Despite their best efforts all Na Piarsaigh could muster up was a mere two points as the Rockies ran out comfortable winners.
Scorers for Blackrock: K O’Keeffe 1-6 (0-5f), E O’Mara 1-2, S O’Keeffe 0-3, D Cremin 0-2, E O’Farrell 0-2, P Deasy, D O’Farrell, C Crowe (0-1 each).
Na Piarsaigh scorers: R Lynch 0-4 (f), A Dennehy 0-3, K Buckley 0-2, C O’Connor, K Waters, S Curtin, C Buckley (0-1 each).
BLACKROCK: P Delaney; S Murphy, A Hayes, R Laide; E Cantwell, A Murphy, C Cormack; E O’Farrell, D O’Farrell; E O’Mara, S O’Keeffe, D Cremin; K O’Keeffe, M Ahern, P Deasy.
Subs: R Dineen for M Ahern (45), C Crowe for P Deasy (48), D Stokes for D O’Farrell (50), L Conway for E O’Mara (55), E Smith for A Murphy (55).
NA PIARSAIGH: A Keating; J McDonnell, A Dennehy, G Long; L Connery, C Joyce, S Curtin; C Buckley, G Joyce; A Hogan, Anthony Dennehy, K Buckley; C O’Connor, K Waters, R Lynch.
Subs: E Hannifin for G Joyce (50), S Warren for K Waters (55).
Referee: C Lyons (Nemo Rangers).