The Dons booked their place in the third round of the Capital One Cup following an exciting come-from-behind victory over Cardiff City at stadiummk.
Carl Baker cancelled out Alex Revell’s opener with 10 minutes remaining to send the tie against the fellow Sky Bet Championship side into extra-time.
Karl Robinson’s men dominated from then on in and deservedly earned a place in the hat thanks to debutant Josh Murphy’s goal in the 108th minute.
Murphy was handed his Dons debut while a host of other players were given match minutes.
Craig Noone and Revell shot over the bar for the visitors in the opening exchanges while, at the other end, Cristian Benavente couldn’t get his 25-yard free-kick on target.
Shortly afterwards, Lee Hodson cleared off the line before Cody Cropper brilliantly denied Eoin Doyle after the ball was recycled on 17 minutes.
The Dons hit back through the lively Murphy, who couldn’t pick out a team-mate after superbly beating his man and getting to the byline.
Murphy & co continued to threaten as the men from MK1 began to look more dangerous with the game approaching the half-hour mark.
Cardiff carried a threat of their own, though, with Stuart O’Keefe forcing Cropper into a smart stop from 12 yards after the ball had fallen kindly to him.
At the other end, Sergio Aguza curled a 25-yard effort just past the post in the last real action of an entertaining first 45.
Aguza again went close at the start of the second half, seeing a low drive deflected behind for a corner after Murphy had got to the byline and delivered the ball into a dangerous area.
Murphy went within inches of breaking the deadlock on 53 minutes, cutting inside the from left and sending an effort narrowly past the far post.
However, the Dons found themselves behind less than 60 seconds later, Alex Revell arriving at the back post and firing O’Keefe’s cross past Cropper.
Doyle almost made it 2-0 four minutes later when he directed a header just wide of the left-hand post.
Samir Carruthers, Rob Hall and Sam Gallagher were all introduced just past the hour mark to try and spark a revival and help find a route back into the tie.
But it was one of the starters – Baker – who levelled matters on 79 minutes, turning the ball home from close range after Hall had seen an effort saved from Murphy’s cross.
Carruthers almost gave the Dons the lead with a sensational volley before Gallagher’s towering header was cleared off the line as the game entered the final five minutes.
The men from MK1 continued to push forward in search of a winner and Hall flashed a cross-cum-shot across the face of goal in the 90th minute.
Despite a late surge of pressure, Karl Robinson’s side couldn’t force a second and the tie went to extra-time with the sides level at 1-1 after 90 minutes.
After working a shooting opportunity, Noone fired wide when well placed while, at the other end, Baker was denied by Simon Moore from a 25-yard free-kick in the first 15-minute period.
The Dons deservedly went in front at the start of the second period of extra-time, Murphy finding the back of the net following some excellent play from Carruthers and Hall, who saw his shot saved.
Noone shot over as the Bluebirds looked for a response but the hosts comfortably saw out the final stages to reach the stage of the competition where the top Premier League sides enter.
MK Dons: Cropper, Spence, McFadzean (c), Upson, Hodson; Aguza (Carruthers 61), Poyet; Baker, Benavente (Hall 61), Murphy; Powell (Gallagher 61).
Unused subs: Martin, Kay, Jennings, Church.
Goals: Baker (79), Murphy (108).