Dublin won their second All-Ireland U21 football title in a dramatic finish at Breffni Park.
But they had to endure a heart-stopping finish, with Donegal skipper Michael Murphy striking the crossbar with a stoppage time penalty.
The Dubs scored their only previous success at this level in 2003, also at the Cavan venue, and while they were vastly outnumbered by Donegal supporters among the 8,492 crowd, there were joyous scenes at the final whistle.
Dublin, with wind advantage, made the early running to launch their challenge with points from Robert McCarthy and Dean Rock, and at the back, Rory O’Carroll dealt competently with anything directed towards Donegal talisman and skipper Michael Murphy.
A couple of Dermot Molloy frees kept the Ulster champions close, but their short passing game often led them into dead ends.
Dublin led by 0-3 to 0-2 at the end of the opening quarter, and eased further ahead with a long range score from Gary Sweeney.
With Sean Murray and Cian Mullins getting the edge at midfield, the Leinster champions stepped up the tempo, and went three clear when wing back Nicky Devereux cleverly rode a couple of tackles and finished with a neat point.
With Murphy isolated up front and largely ineffective, it was a source of significant worry to Tir Chonail manager Jim McGuinness that his side failed to score from play until two minutes before the break.
But they suddenly burst to life, opening up the Dublin defence to create two goal chances for Murphy.
The first, he dragged just the wrong side of a post, but made no mistake with the second, taking substitute Cillian Morrison’s return pass to plant in an empty net.
Amazingly, Donegal led at the break, by 1-4 to 0-6, and the long ball option was now the way to go for Jim McGuinness’ men.
It led to points for Murphy and Morrison as they went two clear, but the Dubs went back in front with a delightfully crafted goal on 47 minutes, sub David Quinn slipping the ball inside for Gary Sweeney to apply a classy finish.
Donegal responded with points from Molloy and Murphy, both from frees, but the Metropolitans had the bit between their teeth, and were determined to hold on.
They appeared to have done just that until the lively Morrison won a penalty deep into injury time, but Murphy was denied by the woodwork.
Dublin: V Whelan, E Culligan, R O’Carroll, D Nelson, J Cooper, J McCarthy, N Devereux (0-1), S Murray, C Mullins, M Coughlan (0-1), T Furman, G Sweeney (1-1), R McCarthy (0-1), D Rock (0-4, 2f, 1 ’45), C Dorney (0-1).
Substitutes: D Quinn for McCarthy (h-t), C Redddin for McCarthy (42), B O’Rourke (0-1) for Furman (48), S McGuinness for Nelson (50), N Brogan for Dorney (73)
Donegal: P Boyle, E Doherty, C Boyle, P McGrath, D Walsh, T McKinley, C Classon, K Mulhern, D Curran, M McHugh, M Murphy (1-2, 1f), D Molloy (0-5, 4f), J Carroll, L McLoone, A McFadden.
Substitutes: C Morrison (0-1) for McFadden (28), D Murphy for McKinley (28), C McGinley for Carroll (63), S O’Kennedy for Curran (67)
Referee: M Duffy (Sligo).
