Slaughtneil's All-Ireland Club Hurling hopes were dashed as 13-man Na Piarsaigh earned a remarkable 3-15 to 3-8 semi-final win at Parnell Park.
The Derry club led 2-6 to 1-6 at half-time and looked likely winners when Na Piarsaigh's Conor Boylan and Tommy Grimes were sent off after the break.
But Na Piarsaigh outscored Slaughtneil 2-5 to 0-2 over the next 25 minutes.
Shane Dowling's third Na Piarsaigh goal was sensational as Gerald Bradley's Slaughtneil goal came too late.
Dowling's half-time introduction help turn the game in Na Piarsaigh's favour as, despite playing most of the second period with 13 players, they upped their workrate and intensity to dominate the Ulster champions.
The Limerick star's third Na Piarsaigh goal in the 52nd minute will be talked about for many a year as he blocked an attempted clearance from Slaughtneil keeper Oisin O'Doherty before gathering the ball and first-timing to the net from 21 metres without even a glance as to where the posts were.
The sensational strike extended Na Piarsaigh's advantage to 3-12 to 2-8 and Bradley's Slaughtneil three-pointer proved academic as Ronan Lynch added three more scores to bring up his individual tally to 14 points for the 2016 champions.
Slaughtneil let glorious opportunity slip
Slaughtneil will wonder how they managed to let the game slip despite their two-man advantage for most of the second half.
But in truth Na Piarsaigh were a completely different outfit in the second period after they had looked lethargic for most of the first half as they allowed a Brendan Rogers inspired Slaughtneil to pick off points unchallenged.
After their heavy defeat by eventual champions Cuala in last year's semi-final, mission one for Slaughtneil was keeping the game alive early on and they did that and more as Cormac O'Doherty's 16th-minute penalty put them 1-4 to 0-3 ahead.
With full-forward Rogers tormenting Na Piarsaigh full-back Mike Casey, the Derry side wasted crucial chances to extend their lead with Gerald Bradley and Shane McGuigan off target immediately after the goal.
Na Piarsaigh levelled the contest in the 22th minute as Conor Boylan lashed to the net after rounding full-back Sean Cassidy but Slaughneil were four ahead again by the 25th minute after Rogers' superb fetch set up Brian Cassidy to net.
Then came one of the big moments of the match as Na Piarsaigh keeper Podge Kennedy made a pointblank save with his helmet to prevent Rogers scoring a third Slaughtneil goal.
Slaughtneil still led by three at the break but there was the sense that they had wasted chances which could ultimately prove crucial.
Dowling orchestrates Na Piarsaigh triumph
It was obvious that Na Piarsaigh's management had delivered a stern talking to their players at the break as two Lynch points quickly reduced the margin to a point.
However, the Limerick side's revival then appeared to have been delivered terminal blows as Boylan and Grimes received straight red cards in a two-minute period following off-the-ball incidents.
However instead of being bowed, the Na Piarsaigh players went on to produce a ferocious display of desire for the remainder of the contest to subdue Slaughtneil.
Dowling was the orchestrator as his superb fetch set up Kevin Downes to net in the 41st minute.
Not helped by a couple of missed Cormac O'Doherty frees, Slaughtneil managed only two points in a 29-minute period and it could have been even worse for the Ulster champions as keeper Oisin O'Doherty brilliantly saved a Lynch penalty on 48 minutes.
But four minutes later, O'Doherty endured heartbreak as Dowling picked his pocked before lashing in his stunning goal.
That was effectively that and the disappointment on the Slaughtneil faces at the end told of the tale of an opportunity they knew they had squandered despite Na Piarsaigh's second-half heroics.
Slaughtneil's dual players now face the task of regrouping for the All-Ireland Club Football semi-final against Nemo Rangers on 24 February.