Ultimately, two second-half goals from Piarsaigh were the catalyst for the city side to pull clear of what had been a stiff challenge, with a fifth added at the death as they posted the all-but-one point of their output from play.
Corner-forwards Evan Sheehan and Daniel McGuire each helped themselves to two goals, while wing-forward Craig Hanifin scored three points and was involved in countless others.
Having led by 1-4 to 0-6 at half-time, Piarsaigh won the second half on a scorelin of 4-3 to 0-4, but Killeagh/Ita’s deserve credit, not least for the way they bounced back from a start which suggested that the game would be a procession.
After early points from Daniel Gunning and Sheehan (two), McGuire struck for a goal in the sixth minute when he gambled on Hanifin’s delivery and was rewarded. They were really in the groove but Killeagh settled, with Kevin Murphy immense at centre-back.
Andrew Leahy, Killian Treacy and Aaron Walsh had points for Killeagh/Ita’s, though when Hanifin responded for Piarsaigh, there was a fear that Killeagh/Ita’s had had their purple patch and not made enough of it.
That theory was rubbished though as Treacy and two long-range dead balls from Murphy had the gap down to one, while goalkeeper Shane Kearney made a great save from McGuire.
A great Keane Kelly-Budds point had the East Cork side level a minute into the second half, but Na Piarsaigh pushed on once more, just when they needed to find something special.
There was a large element of fortune to their second goal as McGuire’s low effort from distance wasn’t gathered by Kearney in the slippery conditions and Patrick Buckley was on hand to help the ball over the line.
Three minutes later, that lead was doubled as Hanifin’s pass placed the ball into Sheehan’s hand and the finish was clinical.
Having worked so hard to get back on level terms, Killeagh/Ita’s found themselves with a massive task again but points by Murphy and Treacy suggested that it wasn’t beyond them.
However, Na Piarsaigh weren’t to be denied, with two Hanifin points followed by McGuire’s second goal as he kicked home after Cormac Murphy’s delivery yielded a scramble.
That made it 4-6 to 0-9 and from there the black-and-amber ship wouldn’t be deviated from its harbour of glory. After Luke Fogarty’s point from Killeagh/Ita’s, Na Piarsaigh and Kearney finished with a flourish.
He got his second goal from McGuire’s pass and then added two late points, with the penultimate of those their only score from a placed ball all night.
Scorers for Na Piarsiagh: E Sheehan (2-4, 1 free), D McGuire (2-0), C Hanifin (0-3), D Gunning, C Murphy (0-1 each).
Scorers for Killeagh/Ita’s: K Treacy (0-3, frees), K Murphy (0-3, 2 frees, 1 65), A Walsh, K Kelly-Budds, A Leahy, L Fogarty (0-1 each).
NA PIARSAIGH: S O’Meara; D Roche, K Power, C Bowen; C O’Flynn, G Healy, D Connery; J Morrissey, P Buckley; D Gunning, A Lehane, C Hanifin; E Sheehan, C O’Connell D McGuire.
Subs: C Murphy for O’Connell (30, inured), B Murphy for Buckley (41), K Forde for Lehane (50).
KILLEAGH/ITA’S: S Kearney; D Hogan, J O’Rourke, E Barron; J Landers, K Murphy, E Fitzgibbon; K Kelly-Budds, C Deane; K Treacy, D Ogbebor, S Walsh; A Leahy, L Fogarty, A Walsh.
Subs: P Leahy for Walsh (50).
Referee: N Wall (Carrigaline).