Ruthless Dubs find cracks in Tyrone armour early on
Joy for fans of Boys in Blue as they make short work of Ulster giants
Barely three minutes had passed before the sheet fell off the bogeyman's head - and the scare factor never came back.
Instead of Tyrone, the terrifying, roaring brute of popular myth and legend, we got 15 men flailing helplessly around like the poor doomed inhabitants of Pompeii as Dublin rained ash and molten lava upon them.
Who would have predicted that total annihilation would be so, well, boring? Even Hill 16 finally fell silent because there was so very obviously only one possible ending.
Only the appearance of Diarmuid Connolly in the final 10 minutes of the game revived their flagging spirits.
Amongst those who turned out to watch the clash were Taoiseach Leo Varadkar, former Taoisigh Enda Kenny, Brian Cowen and Bertie Ahern, former President Mary McAleese and former Ireland international Niall Quinn. Michael Fingleton, the former head of Irish Nationwide Building Society, was also present.
A full house of 92,300 fans had packed into Croke Park for this showdown, set to be the grubbiest fight since, oh, 11 hours beforehand with McGregor v Mayweather.
'Puke football' and relentless defensive tactics v almost robotic levels of fitness and skill - which would win out?
Fans across the divide were predicting trouble.
"It's definitely going to be hard," declared a worried Darragh Kidd (12) from Cabra, there with his uncle Darren (35).
The two of them had watched McGregor's Vegas fight over breakfast. This would be a tougher clash than even that, they believed.
Friends Shaunagh Poyntz (19) and Meibh McKinney from Omagh, Co Tyrone, and Lisa Curran from Strabane, Co Tyrone, were equally concerned for their own side.
"We're very nervous - but we're going to dye our hair red if we get to the final," declared Shaunagh.
Their hair follicles can remain untroubled for another year.
It was nothing more than a merciless game of cat and mouse.
Tyrone put backs up straight away after dropping very deliberately out of the parade just as it neared the Hill in a clear and pointed snub.
It was a bad omen right from the start.
Dublin had discovered the cracks in their armoury and flowed in and out of them like mercury.
Identical twins Tara and Clíona Leslie from Lucan, Co Dublin, had special Diarmuid Connolly T-shirts made up to celebrate his return from a 12-week ban, with 'Guess who's back?' printed on them.
"We'll look a bit odd if he doesn't start," giggled Tara.
They had a bit of a wait and there was a false alarm when a substitution in the last few minutes of the game saw a massive cheer go up for Eric Lowndes.
Connolly flashed up on screen looking glum on the bench - but when manager Jim Gavin finally released him on to the pitch, the Dubs sent a roar of delight up to the heavens.
A stealth bomber kept in reserve, he hadn't been required - but proved to be the cherry on the cake.
Dublin won by 12 points, with a final score of 2-17 to 0-11.
The family of Dublin's Paul Mannion were celebrating.
His mother, Yvonne Donnelly, brother Mark and sister Lucy had watched with bated breath, Lucy revealing how she had teased her brother that morning about it being like he was going off to fight in a war.
"He said 'We are, we are going to war - we're soldiers'," she said.
Time will tell whether Mayo will prove to be a more fitting adversary.