1-03 without reply in the closing four minutes, earned Cavan their fourth Cadbury Ulster Under-21 Football title in a row, following a 2-06 to 0-08 win over Donegal at the Athletic Grounds.
Despite being dominant in all sectors in the opening half, Cavan only led by 1-02 to 0-02 at half-time, and fell two points in arrears with two minutes of normal time remaining, but dug deep to secure victory.
Liam Buachanan's 59th minute goal was Cavan's first score for 21 minutes, and handed the Breffni Blues a lead they wouldn't relinquish, as Peter Reilly's charges held out to retain silverware.
Cavan made one forced change to their side with midfielder Brian Sankey ruled out due to a hand injury, with Liam Buchanan introduced in his place.
Donegal manager Maxi Curran also made one change to his line-up, with Darach O'Connor introduced in place of John O'Malley in attack.
Cavan looked most eager early on to retain silverware, and had the first score after just two minutes, following a Kevin Bouchier pointed free, but the reigning champions struggled to add to their tally.
The five-time champions dominated possession at midfield, with Dara McVeety and Joe Dillon hungry upfront, but Cavan struggled to convert this possession to scores.
Donegal's attacking chances were limited at this stage, but after Barry Fortune drew a foul in the 12th minute, Paddy McBrearty converted the resulting free to tie the match.
Cavan brought their wides tally to four in the 17th minute, before two minutes later Cavan penetrated the Donegal rear-guard, with Dillon bagging the opening goal to push his side 1-01 to 0-01 in front.
Donegal cut the gap thanks to a William Gillespie point, but Cavan then lost their team captain Conor Moynagh on a black card.
Defences continued to stay on top in the closing stages of the half, with just one further score produced as a Kevin Bouchier pointed free ensured a 1-02 to 0-02 interval score-line.
McBrearty and Kevin Bouchier traded points from frees inside the opening eight minutes of the second half, but Cavan struggled for further scores.
Donegal came into their own in the second half, with Eunan Doherty, McBrearty, Martin O'Reilly and Ryan McHugh impressive.
Scores from Hugh McFadden and McBrearty cut the gap to a point by the 44th minute, before scores from McBrearty and Ryan McHugh pushed Donegal 0-07 to 1-03 ahead with six minutes left on the clock.
Cavan continued to work hard, but when Eoin McHugh slotted over an inspirational point to open up a two-point gap it looked like silverware was heading to Donegal.
But Cavan showed great character late on, with Buachanan's goal followed up with injury-time points from Michael Argue, Dillon and Barry Fortune as Cavan claimed victory.
After the game Cavan captain Conor Moynagh lifted the cup, while Joe Dillon claimed the man of the Match award.
CAVAN: J Farrelly; B Fortune (0-01), K Clarke, P Faulkner; G Smith, CP Moynagh, C Brady; L Buachanan (1-00), M Argue (0-01); P Graham, E Flanagan, A Watson; D McVeety, K Bouchier (0-03), J Dillon (1-01).
Subs: A O'Hara for Moynagh (BC 23); T Hayes for Bouchier (39); E Hession for Flanagan (47); C Byrne for Graham (59)
DONEGAL: J Coll; C Brennan, C Parke, A McCloskey; M O'Reilly, R McHugh (0-01), G Gallagher; H McFadden (0-01), C Thompson; D Mulgrew, P McBrearty (0-04, 3f), E Doherty; J O'Malley, W Gillespie (0-01), E McHugh (0-01).
Subs: C Cannon for McCloskey (37); J O'Malley for Doherty (52).
Referee: Cathal O'Hagan (Tyrone)