If this was the last sting of a dying wasp, as many predicted coming into this game, then Donegal's poison was the 1-5 they compiled without reply at the start of the second half to first wipe out Derry's lead, then crowbar open an insurmountable gap.
Six points up with 22 minutes remaining, Donegal amazed with what they are capable of in patches.
Rumours of their demise and all that ...
Not that we have seen much evidence of it, but it has been said that a trip through the qualifiers would not have suited this Donegal team.
They will not have to worry about that now and with the winners of the Fermanagh and Antrim game this Sunday awaiting in a semi-final, it's fairly likely they will feature in their fourth consecutive Ulster final.
Derry will be furious with themselves because it felt as if they melted in Championship heat.
It seemed like Donegal's injury list, along with player departures and suspensions, would torpedo the chances of the 2012 All-Ireland champions.
Their midfield was already stretched with Rory Kavanagh's suspension, but before the game Neil Gallagher and Martin McElhinney were ruled out.
Corner-back Paddy McGrath came in for his first start of the year and schoolboy forward Darach O'Connor also came in as Jim McGuinness was forced to apply a graft to the middle third, Christy Toye and Odhran MacNiallais occupying the midfield positions for the throw-up.
With Derry expected to profit under such circumstances, Fergal Doherty had already cleanly fielded two kick-outs when he collided with a forest of Donegal players on 16 minutes, the impact of the thump forcing him off for Niall Holly and with that, a fair dose of leadership.
Each point in the opening half was carved out of granite. Patience was needed as Donegal employed the defensive structure that has served them well.
When Holly landed a point on 23 minutes, you had to marvel at the labour involved to get a shot on goal that edged Derry 0-4 to 0-3 in front.
A pressure free from Emmett Bradley and a point from Ciaran McFaul opened up Derry's lead and they had shut out Donegal for 14 minutes before Michael Murphy clipped over a free that narrowed the margin to two points at the break.
Furthermore, Derry spurned a goal chance when Holly and Emmett McGuckin were isolated against the lone Donegal defender Neil McGee, but Holly's weak pass along the floor passed up the opportunity.
At half-time, Martin McElhinney replaced Christy Toye in the Donegal engine room.
Anthony Thompson sniped the first point after the Limerick-based Karl Lacey robbed Holly with a smart tackle downfield.
Thomas Mallon's restart was hoovered up by Ryan McHugh, who played towards Murphy –now threateningly employed closer to goal – who laid off to Frank McGlynn.
He advanced, releasing Leo McLoone at the optimum moment, who hit the net with calm assurance.
McHugh won another break in midfield from the next restart, ending in a Murphy point and with the crowd finding their voice, Derry were slowly going under.
The cheers grew louder when a sideline ball just inside the 45-yard line was drilled over by Murphy with the outside of the boot.
Fine margins. Just down the other end prior to that, Derry wing-back Kevin Johnson had stolen instead the Donegal cover, let fly with the boot and was blocked down by Neil McGee.
Murphy added another free and Paddy McBrearty – off-colour in the first half with three shots dropped short and a goal chance blazed wide – again got sight of goal but hammered over the crossbar.
Derry manager Brian McIver sent for Ryan Bell and Benny Heron to spice up his attacking ranks, and they accounted for five of the next six points.
Donegal appeared to have blown themselves up with that massive push in the third quarter, but they might also have been the beneficiaries of some odd decisions by referee Joe McQuillan.
Attempts at tackling that were blown at one end, were only occasionally blown at another.
With Derry enjoying the possession, there were some puzzling moments.
Sean Leo McGoldrick on one occasion dipped to pick up the ball but was rewarded with two Donegal players landing knees on his back. McQuillan signalled play on.
Gerard O'Kane got forward to splice a shot that spilled just the other side of the upright with seven minutes remaining that would have left the minimum in it and nerves frayed.
With Neil Gallagher playing as point-guard at the base of a final attack, Donegal patiently worked themselves into space and McLoone managed to notch another to leave just one goal in it.
Derry's day of misery ended when James Kielt – on a sub for the last 10 minutes – was sent off after compiling a yellow card and a black for a hand trip on Eamonn McGee in injury time.
So, Donegal, eh? They haven't gone away, you know.
DERRY: T Mallon; G McKinless, D McBride, C McKaigue; K Johnston, G O'Kane, SL McGoldrick; F Doherty, P Bradley; C McFaul 0-1, M Lynch (Capt) 0-4, 3f, E Bradley 0-3, 2f; E Lynn, E McGuckin, C O'Boyle. Subs: N Holly 0-1, for Doherty (16m), B Heron 0-2, 1x'45', for Holly (blood sub, 38m), R Bell for O'Boyle (42m), Heron for Holly (48m), O Duffy for Johnson (58m), J Kielt for McGuckin (61m), C McGoldrick for E Bradley (68m)
Yellow cards: Kielt (67m)
Black cards: Kielt (71m)
Red cards: Kielt (71m)
DONEGAL: P Durcan; E McGee, N McGee, R McHugh; A Thompson 0-1, K Lacey 0-1, P McGrath; C Toye 0-1, O MacNiallais; D O'Connor 0-1, L McLoone 1-1, F McGlynn; P McBrearty 0-1, M Murphy (Capt) 0-4, 2f, 1x sideline, C McFadden. Subs: McElhinney 0-1 for Toye (half-time), N Gallagher for O'Connor (42m), David Walsh for MacNiallais (58m), L Keaney for McBrearty (66m), D Molloy for McFadden (68m)
Yellow cards: N McGee (64m)
Black cards: 0
Red cards: 0
Referee: Joe McQuillan (Cavan)
Thomas Mallon: Rarely troubled, deployed his kick-outs to good effect and was left badly exposed for the one that got away.
Gareth McKinless: Charged with curtailing Michael Murphy, he coped well up to half-time but in the third quarter the Donegal skipper cut loose.
Chrissy McKaigue: Picked up Patrick McBrearty and was on his shoulder for the most part but found himself overburdened in the second-half.
Dermot McBride: Sharp in the tackle and alert for the most part, he kept tabs on Colm McFadden making some timely interceptions.
Kevin Johnston: Made a promising start but faded after the break and was replaced by Oisin Duffy in the 60th minute.
Gerard O’Kane: Used as a sweeper in the first-half where he deployed his experience well and looked very comfortable when on the ball.
Sean Leo McGoldrick: Listed at centre-half-forward, to the surprise of no one he was in essence a link between defence and attack.
Fergal Doherty: Lasted only15 minutes until he was forced to retire with a back injury, just as he was beginning to make his presence felt.
Patsy Bradley: Got through a lot of hard, punishing work in the first-half but was soon forced to play second-fiddle.
Enda Lynn: Never able to make any real impact, was surprisingly held scoreless and surrendered possession rather easily.
Mark Lynch: Could never find space in which to unleash his skills although his four points (three frees) helped to sustain his side’s hopes.
Ciaran McFaul: Scored a fine first-half point, looked threatening occasionally but never quite gained a toe-hold in the game.
Emmet Bradley: An 11th-hour inclusion, he swooped for two superb first-half points, looked impressive on the ball but was a fading influence.
Emmett McGuckin: Endured only frustration in his head-to-head with Neil McGee but did not enjoy any real level of quality possession.
Cailean O’Boyle: One of his quietest games in the county colours. He rarely escaped the clutches of Eamon McGee who held him scoreless.
Paul Durcan: His kick-outs were impeccable, he never looked like conceding a goal and his communication with his defence was first-class.
Eamon McGee: Had task of containing Cailean O’Boyle which he fulfilled and still managed to close off other avenues to Derry.
Neil McGee: Pugnacious battle with Emmet McGuckin looked to be on the cards but he shackled the Magherafelt clubman.
Karl Lacey: Kept a tight rein on Mark Lynch in the first-half in particular, popped up everywhere after the break and landed a fine point.
Frank McGlynn: Busy and purposeful, he drove forward with menace on occasions and his precise pass that led to McLoone’s goal was a beauty.
Leon McLoone: His superb goal just after the break tilted the pendulum in his team’s favour while his 70th minute point rocked Derry.
Anthony Thompson: In a golden personal seven-minute spell after the break he scored a point, made another and then asserted his authority.
Paddy McGrath: Started at wing-back and his rugged,|battling approach discomfited Derry with Enda Lynn bearing the brunt of his skills.
Daragh O’Connor: His pace and hunger for the ball saw him prosper in the early stages during which he scored a point but he was sacrificed later.
Christy Toye: Effective and constructive in the first-half when he was on the ball a lot, he was nonetheless replaced at half-time.
Ryan McHugh: Had a lively battle with Ciaran McFaul before going deeper to provide ammunition when Murphy was pushed forward.
Odhran MacNiallais: Not quite as prominent as he was during the league and found difficulty coping with Derry’s tight marking early doors.
Patrick McBrearty: Did not quite deliver as he can but still managed to look dangerous when in|possession.
Colm McFadden: Not quite his usual self, even failing to score – a highly unusual occurrence – and unable to win much possession.
Michael Murphy: Four points (three frees) in a 12-minute spell underlined his massive value to the side as did his skill to fulfil a deeper role.