For 45 energy-sapping minutes in Elverys MacHale Park, there was the semblance of a good old-fashioned Mayo-Dublin duel of the low-scoring league variety.
Then Dean Rock pounced for the only goal, and harsh reality dawned on the embattled hosts: 16 games and counting against the Dubs, and not a single victory to show for it.
In truth, their prospects of ending that eternal winless streak had shipped a sledgehammer blow as early as the 15th minute when one of the Mayo rookies, Jordan Flynn, was red-carded for a high tackle.
Cheered on by the natives in a massive crowd of 15,148, James Horan's men had started with bristling intent ... but once they were left facing the numerical odds, it became a long and increasingly difficult night for them.
They only managed five points with 14 men and, even though still level at the break, you already sensed the game was up.
Dublin manager Dessie Farrell. Photo: Harry Murphy/Sportsfile
So it transpired, even against a Dublin team playing well below their stellar best. Not that it mattered: once Rock had showed his poacher's instinct with a palmed goal that looped beyond Rob Hennelly, they kept Mayo at arm's length.
They settled for a six-point margin in the end, a result that leaves the five-in-a-row All-Ireland champions with three Allianz League points after the first two rounds.
The statistical backdrop to Saturday evening's Division 1 encounter made relentlessly grim reading for home supporters: 15 head-to-heads against Jim Gavin had delivered three draws and 12 defeats over the course of seven seasons.
Senior Counsel for the green-and-red could offer the following defence: no team has pushed Dublin to the brink so frequently in high-wire summer showdowns, reflected in two dramatic deadlocks and three one-point All-Ireland final defeats.
As retired Dub Paul Flynn remarked in Saturday's Herald: "We were just so equally matched. I always thought it was their style that hurt us ... any time we played against Mayo, the next day I could barely walk, I was so stiff and sore because of the runners that they had from deep."
But was this still the case? And did it also apply to spring battle? Mayo have been conspicuously less competitive in league combat ever since they crushed Dublin by 12 points in the corresponding Castlebar fixture eight years ago.
To that you could add the scarring memory of last August, when Dublin's 12-minute power play after half-time obliterated Mayo's previously spiky semi-final resistance.
So this was the back story as Horan – the last Mayo manager to oufox Dublin, not once but twice, in 2012 – sent a combination of gnarled veterans and novices into battle tonight.
Dessie Farrell, in his maiden foray against Mayo, opted for a more proven line-up, selecting ten players who started last year’s All-Ireland final replay against Kerry.
There was also an eye-catching recall for Rory O’Carroll, making his first NFL start since 2015, while Dan O’Brien earned an 11th hour promotion for his full league debut, the Kilmacud clubman having come off the bench against Kerry last weekend.
Yet it was Mayo who exploded from the traps, inspired by a superb point on the run from late call-up Aidan O'Shea inside 25 seconds.
Even though Ciarán Kilkenny equalised after nine minutes, taking on Oisín Mullin from a standing start for a fine score from the right flank, Mayo were still dictating the early play.
They were rewarded with two points from distance - a Diarmuid O'Connor free and a booming effort from James Carr - but then disaster struck after 14 minutes.
Lee Keegan of Mayo in action against Eoin Murchan of Dublin during the Allianz Football League Division 1 Round 2 match at Elverys MacHale Park in Castlebar, Mayo. Photo: Harry Murphy/Sportsfile
Flynn's tackle on John Small was high and reckless, but Barry Cassidy deemed it worthy of the ultimate censure: the Derry referee brandished a straight red, gesturing to his neck by way of explanation.
As the half unfolded, it became a low-scoring war of attrition but 14 Mayomen managed to keep the visitors at bay with points from James Durcan and a Fergal Boland mark.
The latter kept them two ahead, but then Dean Rock's second free and a James McCarthy point restored parity at the midpoint, 0-5 apiece.
Some boos from the disaffected locals greeted Cassidy on his half-time exit - and again on his reappearance. By contrast, Lee Keegan's introduction for the injured Colm Boyle drew a raucous seal of approval.
Then reality intruded: O'Brien capitalised on a clever one-two with Kilkenny to score his maiden league point.
There followed a couple of galling Mayo misses, and then a Dublin goal out of nothing on 45 minutes.
When McManamon crossed from the right corner, there appeared no obvious danger - until Rock leaped at the near post and diverted the ball to the far corner.
Game over? As good as. Not even a black card for the returning Mick Fitzsimons could offer a glimmer for the hosts, who were outscored 0-5 to 0-3 after Rock's game-breaker.
SCORERS – Dublin: D Rock 1-3 (0-3f), J McCarthy 0-2, C Kilkenny, K McManamon, D O'Brien, N Scully, J Small, A Byrne 0-1 each. Mayo: J Durcan (1f), F Boland (1m) 0-2 each, A O'Shea, D O'Connor(f), J Carr, T Conroy 0-1 each.
Mayo: R Hennelly; P O'Hora, O Mullin, B Harrison; M Plunkett, C Boyle, P Durcan; S Coen, D O'Connor; F Boland, A O'Shea, J Flynn; R O'Donoghue, J Carr, J Durcan. Subs: L Keegan for Boyle (inj ht), T Conroy for Carr (ht), K McLoughlin for O'Donoghue (48), J McCormack for O'Shea (55), C Loftus for J Durcan (66).
Dublin: E Comerford; M Fitzsimons, R O’Carroll, D Byrne; J Small, J McCarthy, E Murchan; B Fenton, B Howard; N Scully, K McManamon, D O'Brien; C McHugh, C Kilkenny, D Rock. Subs: P Mannion for McHugh (46), L Flatman for O'Carroll (48), P Small for McManamon (55), A Byrne for O'Brien (57), C O'Shea for Murchan (74).