Noel O'Leary did a superb marking job on Down's dangerman Martin Clarke
Cork produced a second-half comeback to edge out Down by a point in a thrilling All-Ireland football final.
The Rebels missed early goal chances but Down settled to take a 0-7 to 0-2 lead although Cork reduced the margin to 0-8 to 0-5 at half-time.
Down then led 0-9 to 0-5 and 0-10 to 0-7 but Cork hit seven of the next eight scores to lead 0-14 to 0-11.
The Ulster side notched the last two scores but Cork held on to earn a win that they just about deserved.
Daniel Goulding hit nine points for Cork - including two vital '45s in the second half - while Donnacha O'Connor notched five points for the winners as Down's proud record of never having lost an All-Ireland Senior final was ended.
Remarkably Benny Coulter didn't manage a score until Down's penultimate point in the 69th minute while Noel O'Leary did a very effective marking job on the Mourne County's playmaker Martin Clarke.
As expected, Graham Canty did not start because of his hamstring injury but the Cork captain and leader was introduced early in his second half and his arrival appeared to lift his team-mates.
Cork carved open the Down defence on a couple of occasions early on but fail to take the chances.
Firstly, Alan O'Connor fired woefully wide after only 15 seconds as the Down defence endured a nervous opening.
The ball should have been in the Down net a minute later as Ciaran Sheehan's point-blank chance was brilliantly saved by Brendan McVeigh and Sheehan's rebound was then blocked on the line by Daniel McCartan.
Daniel Goulding did put Cork ahead a minute later from a free but as Down settled, points from Daniel Hughes and Paul McComiskey then edged the Mourne County ahead.
McComiskey's point could perhaps have been a goal for Coulter as the unmarked Mayobridge man was screaming for the ball with not a Cork defender in sight.
Goulding's second free of the day levelled matters in the 13th minute but Down then enjoyed a purple patch of five unanswered points.
Two of the points came from Martin Clarke points with his brother John, McComiskey and Hughes were also on target.
At 0-7 to 0-2 behind, Cork looked in big trouble but crucially then outscored Down 0-3 to 0-1 in the five minutes before half-time with Donnacha O'Connor and Goulding registering their first points from play.
McComiskey added to Down's lead after the restart but Cork were beginning to shed the shackles which had characterised their first-half display.
Cork captain Graham Canty lifts the Sam Maguire Cup
Two Goulding frees cut Down's lead to two points but the 44th minute and the influential Canty was by now on the field for Cork.
A superb Mark Poland score increased Down's advantage but Cork, with Nicholas Murphy and Aidan Walsh starting to dominate around midfield, replied with three unanswered points to level with Donnacha O'Connor, Goulding and Ciaran Sheehan on target. Kevin McKernan restored Down's lead on 52 minutes but the superb O'Connor levelled four minutes later and the Mourne County never regained the lead.
Paul Kerrigan's left-footed finish put the rampant Rebels ahead a minute later and Goulding's two long-range efforts had Cork three to the good with 10 minutes of normal time left.
Sloppy Cork play allowed Peter Fitzpatrick to reply on 64 minutes.
By that stage, Down had almost emptied their bench although the calling ashore of McComiskey and Poland appeared strange given their contributions.
Another superb O'Connor point put Cork three ahead again on 67 minutes and while sub Ronan Murtagh replied, Goulding make it 0-16 to 0-13 a minute later.
Coulter flashed over a point with a minute left - when he possibly might have attempted to engineer a goal - while Cork were praying for David Coldrick's final whistle when Hughes fisted over a minute into injury-time.
But crucially, Cork won the ball from the kick-out and then earned a free and the game was up for Down as the Rebel County clinched their first All-Ireland Senior Football title in 20 years.
Cork: A Quirke, E Cadogan, M Shields, R Carey, J Miskella, N O'Leary, P Kissane, A O'Connor, A Walsh, C Sheehan (0-1), P O'Neill, P Kelly, D Goulding (0-9), D O'Connor (0-5), P Kerrigan (0-1). Subs: N Murphy for A O'Connor, G Canty for Kissane, C O'Neill for P O'Neill, J Hayes for Kerrigan
Down: B McVeigh, D McCartan, D Gordon, D Rafferty, D Rooney, K McKernan (0-1), C Garvey, P Fitzpatrick (0-1), K King, D Hughes (0-3), M Poland (0-1), B Coulter (0-1), P McComiskey (0-3), J Clarke (0-1), M Clarke (0-3). Subs: C Maginn for J Clarke, R Murtagh (0-1) for McComiskey, B McArdle for Rafferty, C Laverty for Poland
Referee: D Coldrick (Meath).