An inexperienced Donegal relinquished their grip on the Dr McKenna Cup when they went down at home to Fermanagh.
Donegal needed to win by four points to secure a semi-final place as best runners-up but the prospect of another clash with Tyrone a week before they meet in the National League dulled their motivation.
The home side had added five U-21s to their panel in midweek and all were given debuts, with most of the regulars rested for next week's league opener against Sligo.
For Fermanagh, the win was a confidence booster for new boss John O'Neill, who will be impressed by the display of young guns like Barry Mulrone, Paul McGrath and Paul Ward. Fermanagh led by 0-5 to 0-3 at the break and never looked in danger in the second half.
"We rested a number of the seniors at the start tonight, like Karl Lacey and Neil McGee, because they were carrying knocks and we did not risk Rory Kavanagh at all. But they all should be fine for next Saturday night," said Donegal manager Jim McGuinness.
Scorers -- Donegal: A Hanlon 0-3 (0-1f), J Doherty 0-2, M Boyle, K Lacey 0-1 each. Fermanagh: P Ward 0-4 (1f), P McGrath 0-3 (0-1f); T Corrigan (0-1f), J Connolly 0-2 each, C Flaherty 0-1.
Donegal -- P Boyle; T McKinley, E Doherty, F McGlynn; L Keaney, D Curran, K Cassidy; O Doherty, C Classon; P McNelis, J Doherty, O Mac Niallais; A Hanlon, R McErlean, M Boyle. Subs: K Lacey for M Boyle (21) B Dunnion for McKinley, R Bradley for O Doherty (36), P McGrath for McGlynn (55), N McGee for Classon (57).
Fermanagh -- F Murphy; P Sherry, B Owens, M Jones; P McCusker, B Malone, T McElroy; H Brady, J Melarkey; P McGrath, K Cosgrove, N Cassidy; C Leonard, P Ward, J Connolly. Subs: C Quigley for P Sherry (20), T Corrigan for Leonard (42), C Flaherty for Cosgrove (47).
Ref -- M McErlean (Derry).