When Danny Sutcliffe landed his third point from play with the last act of an intriguing first half, it was enough to edge Dublin into the narrowest of leads, 0-13 to 0-12.
They had finished the half in the ascendant, three late points fuelling the belief that Ger Cunningham's roller-coaster debut campaign was about to soar into a higher stratosphere. An All-Ireland semi-final was within tantalising reach ...
They couldn't sustain it. Or, rather, Waterford moved up a gear and the intensity that has been a Déise hallmark throughout a season that keeps on giving pushed Dublin into a tight corner from which they simply couldn't escape.
And, thus, the outcome that most have predicted came to pass in the opening All-Ireland quarter-final at Thurles. Having survived the rare experience of carrying the favourites' tag, Waterford won by 2-21 to 1-19 and march on, emboldened, to an All-Ireland semi-final where they will once more relish the underdog role that inevitably comes for every pretender facing the Kilkenny behemoth.
And Dublin? An up-and-down summer ends with little ground for complaint.
They battled manfully but couldn't quite match opponents who were that bit hungrier, sharper, less prone to error. The tactic of pushing up on Waterford, in a bid to negate their sweeper system, worked for that first half but conspicuously didn't thereafter.
Waterford's runners had prairies of space to plunder in that second period and duly went for the jugular, never more obviously than in the 66th minute when Patrick Curran and Shane Bennett combined to release Maurice Shanahan for their second goal.
That buried the last lingering hope of an unlikely comeback but, in truth, Waterford's opening three-pointer, almost half-an-hour earlier, was the pivotal score. Which brings us back to Shane Bennett.
Last month this 18-year-old rookie sat his Leaving Cert. Yesterday he hit the ground running on his first SHC start, discommoding no less an opponent than Liam Rushe and others in the Dublin defence with his direct running. He drew a handful of frees in the scoring zone, Shanahan converting four out of five.
Meanwhile, his sliding intervention to hook Peter Kelly, forcing a sideline ball that ultimately led to a stunning over-the-shoulder point from Austin Gleeson, perhaps encapsulated the difference between winners and losers on a slippery afternoon in Semple.
By then, though, Waterford were dominating in most positions. Momentum was theirs. And this was principally because of Bennett's 37th minute goal - a swashbuckling ground stroke thunderbolt that belonged to an era long before this Ballysaggart teenager was born.
Afterwards, Ger Cunningham lamented this as the game's key moment. What will make the concession harder to digest is that it stemmed from a turnover: full-back Cian O'Callaghan was first to the ball but he deigned to control it on his hurl instead of catching the sliotar.
In a flash, Shanahan had picked his pocket and then his clever diagonal pass located Bennett in oceans of space, barely 13 metres from goal. He stopped the ball with his hurl; one waited for him to rise it into his paw.
Instead, he pulled first-time on the half-volley and the shot sped past Gary Maguire before he had time to even set himself.
"It was great, in the midst of all sweepers and systems, that there was a good old-fashioned goal off the ground as well. I jumped off the seat," admitted his manager, Derek McGrath.
Now there was three-point daylight between the sides, and Waterford would land six of the next eight scores to soar seven clear.
Briefly, Mark Schutte reignited flickering Sky Blue hopes with a howitzer of his own, Stephen O'Keeffe getting a stick to his 53rd minute shot but not enough purchase to keep it out.
Ryan O'Dwyer created the goal, due reward for a lung-busting shift. Meanwhile, David O'Callaghan carried the good fight until the death, forcing what appeared a 'professional' foul from Gleeson, who was lucky to escape a second yellow and then added insult to injury by blocking David Treacy's 20m free.
Not that it mattered at this injury-time juncture: Waterford were home and hosed.
Nor did Rushe's subsequent straight red card have any bearing on events, although the Dublin co-captain is bound to regret the moment of madness that saw him lash out with his hurl and catch Shanahan on the helmet.
The Lismore giant had spent most of the afternoon tormenting Dublin with his deadball incisions - eight pointed frees, two '65s' and just one placed ball failure - while chipping in with 1-2 from play and that goal assist.
Now Shanahan added to Rushe's misery by appearing to grab his hurl. Not that this should excuse his petulant retaliation - a pure act of frustration on a day when Dublin's centre-back was never allowed dominate as he had done against Limerick.
So, as Dublin lick their wounds, Waterford continue on their giddy way. Next up the ultimate Black-and-Amber benchmark on Sunday week.
They haven't faced Kilkenny since March of last year, when they endured a 20-point humiliation in Nowlan Park.
"We had a (dressing-room) shut-in that day," McGrath recalled. "That's an admirable parallel to bring forward now in that is the last competitive game we played against Kilkenny. We had fairly strong words in the dressing-room afterwards - not looking for faults, just looking for what direction we wanted to go.
"We had an idea as a management - myself and Dan (Shanahan) in particular - where we wanted to go into the future. We've gone that direction and it has been relatively successful."
Now, though, can they take one more quantum leap?
"This Waterford team definitely believes," Maurice Shanahan proclaimed. "But Kilkenny are there. They're the best team around. Tipperary aren't far off them, but Kilkenny have the All-Ireland and it's up to us to get up there.
"Yeah, we will believe. Whether that's good enough on the day, we'll see, but we'll give them one hell of a battle."
SCORERS - Waterford: M Shanahan 1-12 (8f, 2 '65'), A Gleeson 0-4 (1 sideline cut), Shane Bennett 1-0, C Dunford, K Moran 0-2 each, J Dillon 0-1. Dublin: P Ryan 0-5f, M Schutte 1-2, D Sutcliffe, D O'Callaghan 0-3 each, R O'Dwyer, D Treacy (1 '65') 0-2 each, C Crummey, N McMorrow 0-1 each.
WATERFORD: S O'Keeffe 7; S Fives 7, B Coughlan 7, N Connors 6; P Mahony 7, T de Burca 7, D Fives 7; J Barron 8, A Gleeson 8; M Walsh 6, Shane Bennett 9, J Dillon 6; C Dunford 7, M Shanahan 9, K Moran 7. Subs: S Daniels 7 for Connors (inj 31), P Curran 7 for Dunford (55), T Devine for Dillon (69), Stephen Bennett for Shane Bennett (71), E Barrett for Gleeson (71).
DUBLIN: G Maguire 7; S Barrett 6, C O'Callaghan 6, P Schutte 7; C Crummey 7, L Rushe 6, J Boland 6; J McCaffrey 7, N McMorrow 6; P Ryan 5, R O'Dwyer 8, D Sutcliffe 7; D O'Callaghan 8, C Keaney 5, M Schutte 8. Subs: P Kelly 6 for Barrett (47), C Boland 6 for McMorrow (54), D Treacy 7 for Ryan (64).
WIDES: Waterford 11 (6+5); Dublin 6 (3+3)
YELLOW: Waterford 2 (Gleeson 63, Shanahan 68); Dublin 3 (McMorrow 10, McCaffrey 41, Rushe 43).
RED: Waterford 0; Dublin 1 (Rushe straight red 73).
REF: J Ryan (Tipperary).
ATT: 33,150.
MAN OF THE MATCH: Maurice Shanahan (Waterford).