The last time Mayo beat Dublin, in that epic 2012 All-Ireland semi-final, David Clarke performed sporting heroics. With Dublin reducing a lead that stood at 10 points at one stage to just three, Ciaran Kilkenny, in only his second Championship match, floated a ball over the top that Bernard Brogan gathered before engineering a one-on-one with Clarke in the 66th minute.
In those situations, Brogan rarely flinches. But Clarke had his measure, spreading himself to deny at close range.
It was, arguably, the apex of a thrilling encounter. Mayo steadied, the effect of Clarke's save helping to stem the tide, and, from there, were able to see out a game from there that was getting away from them until his intervention.
Clarke was heroic again on Saturday night against Dublin in Croke Park, just as he was for so much of last summer and especially over the course of Mayo's opening three League games.
His positioning in the first half helped to twice squeeze the odds on Eoghan O'Gara prior to his magnificent save from Michael Darragh Macauley in the 34th minute.
His trio of blocks from Paddy Andrews, though, were a highlight of the night, first from a casually hit penalty, then from a rebound that Andrews tried to place before another follow-up was batted out in dramatic fashion.
Dublin were 1-12 to 0-7 ahead at that stage. There was just 46 minutes gone. Clarke's sequence of saves should have been the shot of oxygen Mayo required to go on and chase the game, if not to win it from that position then at least to lay down a competitive marker for later in the summer.
But they didn't score again. They accepted their fate, rolled away and died to fight another day. Not since the 2006 All-Ireland final against Kerry has a Mayo team performed as badly in Croke Park.
Almost every time since that they've played there, they've given every ounce of themselves, especially since James Horan's reign.
But the spirit that took them from seven points down to draw the 2015 All-Ireland semi-final and took them from five points down to level last year's All-Ireland final deserted them.
There's always another day. But will there be a different day, a different outcome against this Dublin team?
Last Saturday night looked like it was teed up for Mayo. A decent second half to reel in Kerry three weeks ago followed by a big win over Roscommon.
Dublin started without key players - 11 if you want it to stretch it to Cormac Costello and Con O'Callaghan who, no doubt, will show real progression this summer.
Mayo were missing big figures too: the O'Shea brothers Aidan and Seamus, Jason Doherty, Ger Cafferkey and Chris Barrett while Brendan Harrison only came off the bench. But they had sufficient experienced bodies to make that count, just as they did against Kerry.
And they had a good cause. A sequence of 10 consecutive games without a win against Dublin that may mask how competitive they have been in most of those games needed addressing.
This felt like a real opportunity to kill that one, and there was a sense of optimism about.
It can be dressed up to make no difference, that's it's only the League, that the investment of energy to chase after a good start was too great.
And Mayo can comfort themselves by the fact that two years ago they lost by 14 points to Dublin in front of their own home crowd yet still managed to put the squeeze on the Dubs deep into an All-Ireland semi-final replay almost six months later.
But it was impossible to come away from Croke Park feeling that some psychological damage hadn't been inflicted by the nature of this defeat.
That even when Dublin dig down into their vast treasure of reserves they are still coming up with answers to everything thrown at them. Quite clearly the All-Ireland champions still struggle with disciplined massed defence as draws with Tyrone especially and Donegal in the previous weeks illustrate.
Mayo remain in decent shape, comfortably a top three team. And resilience has been their hallmark for so long and again, can be taken to manifest itself in the weeks ahead and into the summer.
But the kicking game they preferred on Saturday just didn't work. Too often the kick to the corner was intercepted by a grateful blue shirt reading it so easily.
Andy Moran was generally under pressure with the few that he got to. Cillian O'Connor just wasn't mapped and the energy that Diarmuid O'Connor normally brings to his game wasn't sufficiently replenished to hurt Dublin in any way.
Inside, they just didn't pose a threat, the failure of any forward to score a point a measure of Dublin's pressure but also their own shortcomings.
With ball in hand and runners coming in support they have always looked a more threatening team. It's what they do best and it's why they need the twin engines of Lee Keegan and Patrick Durcan operating in areas higher up the field. In Fergal Boland they have a player who fits that style too.
Saturday night confirmed that the best defensive fit for Mayo is when Kevin McLoughlin operates that sweeping role. By last year's All-Ireland quarter-final against Tyrone he was perfecting it.
And for all his brilliance, issues around Clarke's kick-outs remain, the reason why the management moved on him between last year's All-Ireland finals.
It wasn't enough to remove him then and it most certainly isn't now, given that he's in the form of life. By our reckoning, he has now made 13 saves from close range, including penalties from David Moran and now Andrews, in this League alone.
But that chipped mid-range kick-out that he sometimes uses is inviting trouble, hanging in the air for too long. Dublin sensed it on Saturday night to rustle up an early goal, just as Kerry did in Tralee. He needs to go longer, harder and faster more often to clear the danger area quicker.
Matching Dublin, even surpassing them, physically has been a key to their relative success in the past but even that couldn't give them a foothold when the heat was raised on Saturday.
"The reality is that we're a better team than we showed there. We didn't feel that we were quite as good as maybe what we made ourselves look like last week," said manager Stephen Rochford."
With both statements he is, of course, correct. But the nagging doubt that this Dublin conundrum is getting bigger for them and the solution is getting more distant is palpable, not just for Mayo but for the game's other protagonists too.