Donegal moved closer to the Division One relegation zone with this defeat at the hands of Cork, who boosted their hopes of a semi-final place.
Defences were well on top in a disappointing first half which saw Donegal establish a 0-5 to 0-3 lead.
Ross Wherity missed a couple of chances to score goals and Cork fought back with seven unanswered points to lead the All-Ireland champions 0-12 to 0-7.
Three late Donegal points, two by Colm McFadden, reduced the losing margin.
Donegal started the game brightly in perfect conditions and led by a point, 0-4 to 0-3, when the home side lost the influential Colm O'Neill, who was carried off with a serious looking leg injury.
Paul Durcan prevented a certain score from Andrew O'Sullivan as the Ulster county extended their lead to two points by the break.
Points by Paul Kerrigan and Paudie Kissane, to one by Michael Murphy, saw Cork move to within a point soon after half-time.
Wherity twice went close to finding the net before Murphy knocked over another free, but Cork soon levelled.
Further scores from Andrew O'Sullivan, Liam Shorten, Aidan Walsh and Paudie Kissane, with the best score of the day, allowed last year's beaten All-Ireland semi-finalists to pull clear, and those two late points by McFadden were scant consolation.