Patrick McBrearty converted a late free to earn Donegal a deserved draw in an absorbing clash in Swords on Saturday.
A replay was the least Donegal merited given that most observers had them one point ahead (2-8 to 1-10) at the end of normal time, but bizarrely Cork were attributed an extra point which required the necessity of extra-time.
It was evident from the early exchanges that there was little to separate these well-matched sides as Cork built an early lead through two points from Jeff O'Donoghue and a fine score from midfielder Stephen O'Mahony.
After a 15-minute delay following an injury suffered by a photographer, Donegal resumed in greater heart, with a McBrearty goal added to by points from Darragh White, Ryan McHugh and Luke Barrett helping them to a 1-4 to 0-5 interval lead.
McBrearty and Brendan McNellis added to that lead on the restart, but Cork hit back superbly through points by O'Donoghue (2) and Michael Vaughan.
Mark Sugrue then added a 42nd-minute goal to push the Rebels two points clear.
But McBrearty sent over two frees to Vaughan's sole effort and the Donegal star then struck a goal from Padraig Doherty's long ball.
Sugrue's late point looked in vain prior to referee Brian O'Shea's controversial decision.
SCORERS -- Cork: M Sugrue 1-1, J O'Donoghue 0-4 (3f), J Corkery 0-3, M Vaughan 0-2, S O'Mahony, D Harrington, J Leahy 0-1 each. Donegal: P McBrearty 2-6 (3f), R McHugh 0-2, D White, L Barrett, B McNellis 0-1 each.
Cork -- S Masters; J Ryan, E Delaney, N McCarthy; L O'Neill, D O'Connell, TJ Brosnan; S O'Mahony, M Howard; G O'Callaghan, M Sugrue, M Vaughan; D Harrington, J O'Donoghue, J Corkery. Subs: S Ryan for O'Callaghan (43), G Barry for O'Neill (43), K Cormican for Brosnan (48), J Leahy for O'Donoghue (59), G Farrell for Howard (67).
Donegal -- C McGlynn; J Campbell, A Blair, A McCloskey; M Reilly, P Doherty, S Ellis; D White, L Barrett; S McGarvey, J O'Malley, R McHugh; B McNellis, P McBrearty, S Boyle.
Subs: C Doherty for Ellis (64), R Dunleavy for McGarvey (65), N Breslin for Boyle (70).
Ref -- B O'Shea (Dublin).