They trailed for the large part but two goals in the space of four minutes turned the tide in their favour, completing a record fourth title as this grade in the process.
There was an even opening to affairs as John Heraty and Eoin Delaney opened up the scoring for Mayo only to see their efforts cancelled out at the opposite end by Brian McIntyre and Ruairí Campbell.
Donegal’s Danny Cullen and Mayo’s Shane Boland exchanged points with the teams deadlocked at 0-5 apiece by the end of the first quarter following an excellent Boland point from play.
Mayo seized the initiative as the contest progressed, hitting three points in quick succession through Boland, Bobby Douglas and Cormac Philips with Douglas preserving his team’s lead with a fine stop to deny Liam McKinney a Donegal goal in the 28th minute.
Donegal’s shooting undermined some impressive approach play and Mayo took advantage to extend their lead to four points by half-time, with Delaney, Seán Kenny and Boland all on target.
Mayo continued to keep their opponents at arm’s length in the early stages with Boland and Liam Lavin impressing but Donegal were handed a lifeline as Campbell followed up smartly to flick past Douglas in the 45th minute.
Boland ensured that Mayo’s lead remained a healthy one but that changed in an instant as Cronolly McGee scored a fabulous goal in the 61st minute, leaving Douglas helpless with a rising shot.
His second goal, three minutes later, was less spectacular but had added significance as he rolled home following a goalmouth scramble, leaving Donegal with sufficient momentum to claim a spirited victory.
Scorers – Donegal: G Gilmore 0-6 (2f, 1 ’65); R Campbell 1-3; J Cronolly McGee 2-0; S McVeigh, L McKinney, D Cullen 0-2 each; B McIntyre, P Kelly 0-1 apiece. Mayo: S Boland 0-9 (4f); L Lavin, S Kenny 0-3 each; E Delaney 0-2; B Douglas (f), J Heraty, S Regan, A Philips, C Philips 0-1 apiece.
Donegal: L White; C Curran, S Gillespie, G Browne; S McBride, J O’Loughlin, S McVeigh; G Gilmore, C O’Grady; C Gartland, L McKinney, B McIntyre; S Ward, D Cullen, R Campbell. Subs: J Cronolly McGee for O’Loughlin (h-t), P Kelly for McIntyre (h-t), O Grant for Ward (h-t), R McDermott for Gartland (48), P Doherty for Browne (59).
Mayo: B Douglas; S Kenny, O Greally, C Murray; C Hession, D Kenny, E Collins; D Huane, J Heraty; S Regan, A Philips, L Lavin; S Boland, C Philips, E Delaney. Subs: K Feeney for A Philips (52), M Farrell for Heraty (64), J Burke for C Philips (65).
Ref: P Owens (Down).