Charlton Athletic came from behind and scored deep into added time to secure promotion to the Sky Bet Championship at the expense of Sunderland at Wembley Stadium.
The Addicks made the worst possible start, with Naby Sarr's own goal gifting Sunderland the lead within the opening five minutes. They fought back and went into the break on level terms, though, after Ben Purrington finished an excellent team move.
Chances were few and far between in the second half, but it was the last one of the afternoon which mattered most, as Patrick Bauer popped up to fire Charlton to promotion and break Sunderland hearts.
Lee Bowyer named a youthful Charlton side ahead of the game, with six of his starting 11 aged 23 or younger. Sunderland's line-up, meanwhile, was packed with experience, including the likes of Lee Cattermole, Grant Leadbitter and Chris Maguire.
And it was Maguire who had the first opening of the game on four minutes, with his volley saved by Dillon Phillips in the Addicks goal. The keeper's next action just seconds later, however, is one he will want to forget.
A lapse in concentration saw Sarr's back-pass go straight under Phillips' boot and into his own net, a moment during which time seemed to slow down. Charlton had it all to do, and with only five minutes on the clock.
Sunderland had an issue of their own though, with tough-tackling midfielder Max Power forced off through injury within the opening 10 minutes, adding to what was an incredible start to the game. The Black Cats came forward again though, with Phillips making a fine stop to deny Leadbitter.
On 26 minutes, Charlton's top scorer Lyle Taylor got his first look-in, after getting onto to the end of a diagonal ball, but volleyed over the bar. Their next opportunity, though, brought the equaliser, to huge celebrations in the west side of the ground.
A flowing move involving Joe Aribo and Taylor saw the latter whip an inviting cross right across the face of goal, and Purrington was there to tap home, leaving the game finely poised going into the break.
With the tension and the noise levels through the roof at Wembley, Charlton looked to pick up where they had left off after the restart. Taylor attacked down the right with several red shirts in support, but a strong challenge from Tom Flanagan stopped him in his tracks.
At the other end, Maguire played a good ball in towards substitute Lewis Morgan, who couldn't sort his feet out in time to direct his effort on target. Shortly after, Jack Ross made a second change, with Will Grigg introduced from the bench.
Both sides were defending well, and the second period was one of few clear-cut chances. Former Sunderland man Jonny Williams came on for Charlton, with the Black Cats introducing Aiden McGeady for the closing stages.
Sunderland pressed for a late winner in normal time, with Grigg's dangerous header back across goal cleared to safety but, deep into added time, it was the Addicks whole stole the show, and secured a place in the Sky Bet Championship.
An inviting cross was stood up to the back post, where big centre-back Bauer was waiting to pounce, and pounce he did. Charlton are going up!
Charlton: Phillips, Dijksteel, Bauer, Sarr (Pearce 45'), Purrington, Cullen, Bielik, Pratley (Williams 71'), Aribo, Parker, Taylor.
Subs not used: Maxwell, Solly, Lapslie, Forster-Caskey, Reeves.
Sunderland: McLaughlin, Oviedo, Ozturk, Cattermole, Maguire (Grigg 57'), Wyke (McGeady 72'), Honeyman, Flanagan, O'Nien, Leadbitter, Power (Morgan 9').
Subs not used: Stryjek, Matthews, Gooch, Dunne.
Booked: Grigg, O'Nien, Leadbitter, Flanagan