Sunderland scored four goals in the last 12 minutes to knock Milton Keynes Dons out of the Capital One Cup.
Patrick Bamford fired the League One side in front from 20 yards and Izale McLeod's deft chip doubled the lead.
Jozy Altidore's first goal for Sunderland began a stunning fightback.
Substitute Connor Wickham levelled after a neat passing move and then made it 3-2 to the Premier League hosts with a deflected strike, before Adam Johnson wrapped up the win from a tight angle.
The final outcome was cruel on MK Dons, who looked as though they would record one of the shocks of the second round for much of the tie.
But Karl Robinson's team suffered a League Cup exit at the hands of the Black Cats for the second year in succession, as Paolo Di Canio's men ended their winless start to the season.
Sunderland also knocked Milton Keynes Dons out of the Capital One Cup in 2012-13, winning a third-round tie 2-0 with second-half goals from Craig Gardner and James McClean.
The visitors took an early lead through on-loan Chelsea teenager Bamford, who drilled a left-footed effort past debutant goalkeeper Vito Mannone.
Altidore hit a post for the hosts in the closing stages of the first half, while McLeod missed a golden opportunity to double the lead, shooting wide when clean through on goal.
But McLeod made no mistake when presented with a similar opportunity in the opening stages of the second period, lifting the ball over the advancing Mannone to establish a two-goal advantage.
Di Canio, who named record signing Steven Fletcher on the bench after five months out with an ankle injury, chose instead to turn to Wickham, Larsson and Greek youngster Charalampos Mavrias in an attempt to get back into the match.
Altidore's first goal in Sunderland colours, set up by Wickham, started the comeback on 78 minutes, before the England Under-21 striker converted Ondrej Celustka's cross to equalise.
Wickham's second, a long-range shot that deflected off Dons defender Ben Reeves past goalkeeper Ian McLoughlin, completed the turnaround, while Johnson's mazy run and finish from an acute angle sealed Sunderland's passage into round three.
Sunderland manager Paolo Di Canio: "It was very bad, but I know also it is easy to play badly in this game. Unfortunately, it happens even to the top clubs who play with the top players in this league.
"It's something that I have thought for many years - why do top teams in the cup in England have to go out easily against League One and League Two sides? I don't understand, but I understand [now].
"I was worried, and I was right, but I took something really good from the last 15 minutes - the ambition, the desire, the pride and the goals that we scored in style.
"I am very, very happy for 15 minutes, but I am very, very angry for 75, so the balance is not very good."
MK Dons manager Karl Robinson: "I have just gone in and had a bit of an argument with some of the players because I went in and said 'well done' and they are disappointed at not winning here tonight, so that in itself is a tremendous testament to them.
"I have got young kids - Dele Alli has just turned 17 and I think you will be writing an awful lot of lines about this young boy many, many times because he's as good as I've seen.
"You have all seen tonight that he's destined for going in one direction. He's got all the attributes. He's in there fuming that we have been beaten at 17 years of age."
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Live Text Commentary
Full Time The game is over, as the referee blows the whistle.90:00 +6:01 Booking
The referee cautions Adam Johnson for unsporting behaviour.90:00 +5:20 Goal scored
Goal! - Adam Johnson - Sunderland 4 - 2 MK Dons Adam Johnson scores a right footed goal. Sunderland 4-2 Milton Keynes Dons.90:00 +3:30
Free kick taken by Vito Mannone.90:00 +2:50
Free kick taken by Ian McLoughlin.90:00 +2:31
Free kick awarded for a foul by Sebastian Larsson on Stephen Gleeson.90:00 +2:21
Corner from the left by-line taken by Sebastian Larsson.90:00 +1:36
Free kick taken by Jack Colback.90:00 +1:17
Foul by Alan Smith on Charis Mavrias, free kick awarded.90:00 +0:38
Corner taken by Jason Banton from the left by-line.88:43
The assist for the goal came from Jozy Altidore.88:43 Goal scored
Goal! - Connor Wickham - Sunderland 3 - 2 MK Dons Connor Wickham scores a right footed goal. Sunderland 3-2 Milton Keynes Dons.87:42
Ian McLoughlin takes the free kick.87:27
Charis Mavrias challenges Jon Otsemobor unfairly and gives away a free kick.86:53 Booking
Ian McLoughlin booked for unsporting behaviour.86:14
Assist on the goal came from Ondrej Celustka.86:14 Goal scored
Goal! - Connor Wickham - Sunderland 2 - 2 MK Dons Connor Wickham grabs a goal with a right foot finish. Sunderland 2-2 Milton Keynes Dons.83:26
Corner from the left by-line taken by Stephen Gleeson.
Corner from the right by-line taken by Shaun Williams.82:29
Alan Smith takes the free kick.81:59 Substitution
Substitution Izale McLeod goes off and Luke Chadwick comes on.81:34 Booking
Valentin Roberge booked.81:29
Valentin Roberge concedes a free kick for a foul on Izale McLeod.78:36
George Baldock takes the free kick.78:28
David Vaughan challenges Alan Smith unfairly and gives away a free kick.77:10
The assist for the goal came from Sebastian Larsson.77:10 Goal scored
Goal! - Jozy Altidore - Sunderland 1 - 2 MK Dons Jozy Altidore scores a right footed goal. Sunderland 1-2 Milton Keynes Dons.76:36
Strike comes in from Stephen Gleeson from the free kick and misses left of the target.76:04
Valentin Roberge challenges Stephen Gleeson unfairly and gives away a free kick.74:33
Jason Banton takes the chance to get an effort at goal. Vito Mannone catches the ball.73:16
Free kick taken by Ian McLoughlin.73:02
Connor Wickham is caught offside.72:11
Jack Colback restarts play with the free kick.72:04
George Baldock gives away a free kick for an unfair challenge on Jack Colback.69:21
Alan Smith manages to make a clearance.69:13
Corner taken by Sebastian Larsson.67:44
Shot by Adam Johnson.66:49
Shot by Jozy Altidore went over the bar.66:05 Substitution
Substitution Jon Otsemobor on for Patrick Bamford.65:47 Substitution
Substitution Jason Banton replaces Samir Carruthers.65:06
Patrick Bamford takes a shot and missed to the right of the goal.64:12 Substitution
Substitution Charis Mavrias replaces David Moberg Karlsson.61:48
Free kick taken by Shaun Williams.61:31
Izale McLeod fouled by Valentin Roberge, the ref awards a free kick.60:03 Substitution
Substitution Sebastian Larsson joins the action as a substitute, replacing Adilson Cabral.59:01
Clearance by John O'Shea.58:55
George Baldock takes the free kick.58:50
Patrick Bamford fouled by Jack Colback, the ref awards a free kick.58:16
Ondrej Celustka takes a shot and went wide of the left-hand upright.56:57
Free kick crossed by Shaun Williams.56:47
George Baldock fouled by Jack Colback, the ref awards a free kick.55:57
Shot by Connor Wickham went wide right of the net.55:49
The ball is sent over by Jack Colback.54:59 Goal scored
Goal! - Izale McLeod - Sunderland 0 - 2 MK Dons Izale McLeod scores a right footed goal. Sunderland 0-2 Milton Keynes Dons.52:00
Ian McLoughlin takes the free kick.51:43
Free kick awarded for an unfair challenge on Antony Kay by Jozy Altidore.51:08
Free kick taken by Antony Kay.50:53
The referee blows for offside.50:00
Free kick taken by Stephen Gleeson.49:53
Unfair challenge on Shaun Williams by Jozy Altidore results in a free kick.49:21
Ian McLoughlin restarts play with the free kick.48:58 Substitution
Substitution (Sunderland) makes a substitution, with Connor Wickham coming on for Dong-Won Ji.48:37
The assistant referee signals for offside against David Moberg Karlsson.48:18
The ball is crossed by Patrick Bamford.46:11
Stephen Gleeson takes the chance to get an effort at goal and missed to the left of the net.45:01
The referee gets the second half started.45:00 +3:06 Half time
Half Time The first half comes to an end.45:00 +1:52
Bamidele Alli takes a shot.45:00 +0:36
Free kick taken by Stephen Gleeson.45:00 +0:21
Unfair challenge on Izale McLeod by David Vaughan results in a free kick.44:12
Chance falls to David Moberg Karlsson who heads at goal. Ian McLoughlin safely holds on.43:55
Jozy Altidore takes a shot and bounces off the post.43:19
Valentin Roberge makes a clearance.43:13
Stephen Gleeson takes the free kick.42:44
Foul by David Vaughan on Alan Smith, free kick awarded.35:31
Shaun Williams produces a shot on goal direct from the free kick. Vito Mannone catches the ball.34:50
Unfair challenge on Samir Carruthers by John O'Shea results in a free kick.34:23
Free kick taken by Stephen Gleeson.34:14
Adilson Cabral gives away a free kick for an unfair challenge on Alan Smith.33:28
Free kick taken by Stephen Gleeson.33:19
Valentin Roberge challenges Alan Smith unfairly and gives away a free kick.31:46
Jack Colback takes a shot and cleared the bar.31:31
Shaun Williams manages to make a clearance.31:27
A cross is delivered by Adam Johnson.30:02
Antony Kay takes the free kick.29:48
Bamidele Alli fouled by Jozy Altidore, the ref awards a free kick.28:47
Header by Adam Johnson goes harmlessly over the bar.28:14
Free kick crossed by David Moberg Karlsson.27:54
George Baldock receives a caution for unsporting behaviour.27:54 Booking
George Baldock concedes a free kick for a foul on Jozy Altidore.26:37
Adilson Cabral restarts play with the free kick.26:30
Free kick awarded for a foul by George Baldock on David Moberg Karlsson.25:07
Jack Colback has an effort at goal and missed to the right of the target.24:58
Clearance made by Antony Kay.24:52
The ball is sent over by Adam Johnson.21:10
Clearance made by Shaun Williams.21:03
The ball is swung over by Jack Colback.20:28
Free kick taken by David Vaughan.20:20
Stephen Gleeson concedes a free kick for a foul on Dong-Won Ji.18:55
Shot by Izale McLeod went wide of the right-hand upright.17:57
Jozy Altidore shoots direct from the free kick. Ian McLoughlin safely holds on.17:16
Jozy Altidore fouled by Patrick Bamford, the ref awards a free kick.16:31
Valentin Roberge restarts play with the free kick.16:22
Izale McLeod is caught offside.12:38
The ball is swung over by Adam Johnson.10:48
Clearance made by Vito Mannone.10:42
Corner taken by Stephen Gleeson from the right by-line.10:04
Stephen Gleeson crosses the ball in from the free kick.9:49
Free kick awarded for an unfair challenge on Izale McLeod by John O'Shea.9:33
Ian McLoughlin restarts play with the free kick.9:05
Free kick awarded for an unfair challenge on Shaun Williams by John O'Shea.8:57
David Vaughan takes the free kick.8:52 Booking
The referee shows Patrick Bamford a yellow card.8:45
Jack Colback fouled by Patrick Bamford, the ref awards a free kick.6:15
The assist for the goal came from Bamidele Alli.6:15 Goal scored
Goal! - Patrick Bamford - Sunderland 0 - 1 MK Dons Patrick Bamford slots the ball left footed into the goal. Sunderland 0-1 Milton Keynes Dons.3:40
Free kick taken by Valentin Roberge.3:34
Jack Colback fouled by Stephen Gleeson, the ref awards a free kick.3:07
Shaun Williams takes the free kick.3:01
Free kick awarded for a foul by Jozy Altidore on Bamidele Alli.2:39
Vito Mannone restarts play with the free kick.2:21
Izale McLeod gives away a free kick for an unfair challenge on Valentin Roberge.1:39
Ondrej Celustka restarts play with the free kick.1:34
Free kick awarded for a foul by Shaun Williams on Dong-Won Ji.0:00
The referee gets the game underway.
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