Donegal produced a huge shock as they earned a comprehensive 3-14 to 0-17 win over champions Dublin in the All-Ireland Football Semi-Final.
Dublin looked in control as they led 0-7 to 0-2 but they missed two great goal chances and Ryan McHugh's goal helped Donegal lead 1-8 to 0-10 at half-time.
A second McHugh goal straight after the restart further stunned the Dubs.
Colm McFadden's three-pointer helped Donegal lead by eight points as there was to be no road back for the holders.
Dublin went into the game watched by over 81,000 spectators as 10/1 on favourites but after producing a impressive opening quarter, the 'team that couldn't be beaten' wilted as their composure deserted them.
But while there will be major inquests in the Irish capital about what went wrong for Jim Gavin's side, those discussions shouldn't overlook a quite remarkable display by the rejuvenated 2012 All-Ireland champions.
Donegal were back to the marauding form of two years ago as their massed defence forced turnovers which led to lightning breaks into Dublin territory.
Both teams made late changes to the line-ups with Cormac Costello and Jack McCaffrey replacing Kevin McManamon and Nicky Devereux for Dublin and David Walsh and Rory Kavanagh in for Patrick McBrearty and Christy Toye.
Jim Gavin's changes certainly didn't work for Dublin although McManamon and Devereux made little impact when they were introduced in the second half.
Walsh was quickly called ashore after 25 minutes and Toye's introduction helped Donegal fight back after Dublin's early scoring blitz while McBrearty's impact role in the second half was again a boon for Jim McGuinness's side.
Dublin seemed to have uncovered the key to unlocking Donegal's massed rearguard as spearheaded by Paul Flynn, they racked up a 0-7 to 0-2 lead by the 19th minute thanks to some glorious long-range shooting.
But crucially, the Dubs had wasted their first goal chance as the struggling Eoghan O'Gara, shackled throughout by Neil McGee, failed to find the unmarked Bernard Brogan.
Dublin's second big miss came when they led 0-8 to 0-4 as Diarmuid Connolly's low point-blank shot was saved by Paul Durcan when the roof of the net should have been bulging.
The Dubs still looked in control as a Connolly score did increase their lead to five but the remainder of the half belonged to the Ulster champions as they outscored the opposition 1-5 to 0-1 in an astonishing 10-minute period.
Toye started the Donegal scoring sequence and after points by Odhran MacNiallais and Michael Murphy, the Ulster champions suddenly were in the lead when McHugh poked to the net after an unselfish lay-off from Colm McFadden following a high ball aimed in at Murphy.
While Donegal led 1-8 to 0-10 at the break, Dublin fans were surely expecting normal service to resume in the second period, such was the pre-match talk of the gulf in class between the teams.
But the home supporters were in for a rude awakening as Donegal ripped up the Dublin defence on numerous occasions in the second period.
Anthony Thompson's run set up McHugh to score his second goal three minutes after the restart as Dublin were caught short in defence.
McFadden bore down on the Dublin's goal again two minutes later but was content to fist over another point.
Dublin briefly threatened a revival as the Brogan brothers Alan and Bernard swung swung over two scores in a minute as Gavin introduced his regular super-sub McManamon.
However, the match was close to being put to bed with a full 23 minutes of normal time left as McFadden was able to walk the ball into the net after great work by MacNiallais with the Dublin defence again hopelessly outnumbered.
Dublin did cut the lead to five points by the 57th minute after points from sub Paddy Andrews and Connolly but not even the black carding of Eamonn McGee for a body-check on Jonny Cooper was going to rattle Donegal as McBrearty responded with two glorious points from distance.
The defending champions frantically chased goals in the final 10 minutes but their shooting was wildly off target as Michael Darragh Macauley, Connolly and McManamon all blazed wide.
Another tactical masterclass from Jim McGuinness had won the day as Donegal fans celebrated raucously.
Donegal: P Durcan; E McGee, N McGee, P McGrath; A Thompson, K Lacey (0-1), F McGlynn (0-1); N Gallagher, O MacNiallais (0-1); David Walsh, L McLoone, R McHugh (2-2); R Kavanagh (0-1), M Murphy (0-3), C McFadden (1-3). Subs: C Toye for David Walsh, P McBrearty (0-2) for L McLoone, Declan Walsh for N McGee (blood), M McElhinney for R Kavanagh, D O'Connor for C McFadden, M O'Reilly for O MacNiallais
Dublin: S Cluxton; M Fitzsimons, R O'Carroll, P McMahon (0-1); J McCarthy, J Cooper, J McCaffrey; M D Macauley, C O'Sullivan; P Flynn (0-4), A Brogan (0-2), D Connolly (0-5); C Costello, E O'Gara, B Brogan (0-3). Subs: N Devereux for J McCaffrey, K McManamon for C Costello, D Rock for E O'Gara, P Andrews (0-2) for A Brogan, D Daly for J Cooper, P Mannion for C O'Sullivan.
Referee: J McQuillan (Cavan)