SEAN O'Hanlon scored the decisive penalty as MK Dons won a shoot-out to shock Ipswich and progress to the second round of the Carling Cup following a 3-3 draw AET.
Skipper O'Hanlon held his nerve to seal a 5-3 penalties victory for Paul Ince's League Two side at stadium:mk, after Dan Harding's spot-kick had been saved by Dons goalkeeper Nathan Abbey.
The Dons, who hit the woodwork three times, had raced into an early 2-0 lead thanks to Leon Knight's strike and Alex Bruce's own goal.
But Alan Lee's penalty and Kieran Murphy's own goal drew the Tractor Boys level before Kevin Gallen's 120th minute spot-kick took it to penalties after Owen Garvan had put Town 3-2 up in extra-time.
The re-shuffled Dons dominated the first half and Knight capped a superb passing move by deservedly putting them ahead in the 16th minute, just moments after he had hit the bar with a close range diving header.
Aaron Wilbraham slipped a well-weighted pass down the right channel to Alan Navarro, who cut the ball back perfectly from the by-line for Knight to ram in his first goal of the season from eight yards.
And then Ipswich centre-half Bruce's comical own goal gifted Milton Keynes a 2-0 lead just five minutes later.
Bruce appeared under little pressure as Jon-Paul McGovern's corner curled in towards him seven yards out but he inexplicably headed the ball past Town goalkeeper Neil Alexander and into his own net via the underside of the bar.
The lacklustre Tractor Boys upped their game towards the end of the first half and Lee pulled a goal back from a controversial penalty on the stroke of half-time, just moments after he had been denied by a brilliant double-save from Dons goalkeeper Nathan Abbey.
MK midfielder Navarro was adjudged to have brought down Gary Roberts in the box although he looked to have got a touch on the ball, and Lee duly sent Abbey the wrong way from the spot for his third goal of the season.
Dons striker Knight was unlucky soon after the re-start when his cheeky 10-yard back-heel was hacked off the goal-line by Town skipper Jason De Vos, after keeper Alexander had dropped Mark Wright's cross.
But Murphy's own goal at the other end gifted Ipswich an equaliser to make it 2-2 sevens minutes after the break.
Pablo Counago stole a yard on Sean O'Hanlon to cross low into the box and the sliding Murphy diverted the ball past keeper Abbey and into his own net from six yards.
The fired-up Dons sprung back into life and Knight volleyed just wide under pressure before he somehow fired against the woodwork for the second time from three yards after O'Hanlon's header had been pushed out by Alexander in the 63rd minute.
And substitute Lloyd Dyer made it a hat-trick of woodwork hits for the unlucky Dons when his sublime 18-yard curler struck the outside of the post in the 76th minute.
Ipswich substitute Danny Haynes was denied by a super double-save from Dons keeper Abbey three minutes from the end as the game finished 2-2 after normal time.
Garvan's header from substitute Danny Haynes' cross put Ipswich ahead eight minutes into extra time but substitute Gallen's last-gasp spot-kick drew Dons level after Knight had been dragged down in the box by Jason De Vos, before O'Hanlon's winning penalty.
MK Dons: Abbey, Stirling, Lewington, O'Hanlon (c), McGovern (Dyer 59,), Knight, Wright, Wilbraham, Murphy, Navarro (booked for foul 29) (Edds 84), Howell (Gallen 96). Subs: Gallen, Dyer, Gueret, Edds, Carayol.
Ipswich Town: Alexander, Wright, Lee (Legwinski 77), Miller, Garvan, Harding (booked for dissent 67), Roberts (Haynes 46), Bruce, De Vos (c), Walters, Counago (Clarke 77, booked 82). Subs: Supple, Wilnis, Legwinski, Clarke, Haynes.
Referee: Paul Taylor (Herts).