Sunderland have been relegated to the third tier of English football for only the second time in the club's history after losing a dramatic relegation battle with Burton 2-1.
Paddy McNair gave the Black Cats the lead 11 minutes before the break - but two goals in the last four minutes relegated the Black Cats and moved Burton to within two points of safety.
Former Sunderland striker Darren Bent came off the bench and headed in the equaliser, before Liam Boyce nodded the winner deep into added-time.
There was more drama seconds later when McNair had an equaliser ruled out for handball by the referee's assistant, even though the man in the middle Darren England had given the goal at first.
Sunderland headed into the game on the back of three spirited displays, all draws - but both teams knew a victory was essential to keep their slim chances of survival alive.
Burton did not start the game in the sort of manner that saw them defeat neighbours Derby in their previous outing, allowing the home side more time on the ball.
Despite Sunderland's more positive start there was a lack of threat posed to the goalkeepers and apart from McNair's opening goal there were no serious saves to make.
Jason Steele, back in between the posts after Lee Camp was left out, held everything that came his way and was in the way of a couple of efforts that were driven into him.
Stephen Bywater, at the opposite end, could not do the same. Even though he did dive left to gather a McNair strike after Callum McManaman's touch earlier in the half, the goalkeeper got his positioning wrong for the next.
Ashley Fletcher did well to cut inside from the left and dribble beyond a couple of players. Just when it seemed he would be stopped, he poked a pass in the direction of McNair - who drilled low from 20 yards into the centre of Bywater's net.
Burton had the greater share of possession after the restart and pressed in the hope of finding an equaliser but they still lacked a cutting edge.
The nearest they came in the early stages of the half was when Lucas Akins' delivery from the right caught out Sunderland's defenders but they did enough to clear.
Steele turned away a Jacob Davenport free-kick with 20 minutes remaining and that led to a tense finale when the stage was set for Bent.
The experienced striker, booed throughout after he was introduced, headed over the line from close range after Steele - who also saved another volley from the former England striker - had done well to save Hope Akpan's long-range strike.
Then Burton turned the game completely on its head when Boyce glanced in the winner deep into stoppage-time.
There was still time for McNair to have an equaliser ruled out for handball - and the final whistle soon after confirmed Sunderland's relegation.
The managers
Chris Coleman: "Firstly I would like to apologise to everyone for coming up short, ultimately not having what was needed. It's a brutal experience and the disappointment is huge. To be fair, maybe blind optimism, five minutes left, I thought we were in the driving seat even though we didn't play well. Five minutes left the atmosphere was great, then it all changed.
"Forty-four games we are into the season and we haven't been good enough. I am sorry for the supporters who have stuck with us every week, followed us, we haven't had enough and we have fallen short. I don't know where this club goes. I don't know what the plan is. We have been looking in terms of recruitment and players.
"We have not been told what's what. When I speak with chief executive Martin Bain he is as much in the dark as me. We know where we are now and we have to say 'that's happened, this is the plan'. Right now it's very raw, it's just happened. It's brutally painful. I have been here two minutes, the supporters have been here for years I can only imagine how they are feeling. I don't know what the plan is."
Nigel Clough: "I have unbelievable sympathy for Sunderland. He (Brian Clough) used to talk with such affection about the people, he so enjoyed his time here. It's just a time for them to take stock and rebuild, plenty of clubs have gone into League One ... Wolves, Leicester ... it's tough to get out of."