Source: Eurosport
Scunthorpe edged through to the Coca-Cola League One play-off final after a
Iron goalkeeper Joe Murphy saved two spot-kicks before former Chelsea striker Tore Andre Flo thumped his side's eighth penalty against the crossbar.
The result denied Robert Di Matteo, a three-time cup-winning goalscorer with the Blues, a chance to return to Wembley in his first season as a manager.
Instead Scunthorpe, themselves Wembley losers in the Johnstone's Paint Trophy against Luton a month ago, have the chance to bounce straight back to the Championship when they face Millwall in the capital a week on Sunday.
Aaron Wilbraham should have broken the deadlock for the Dons in normal time, while Iron defender David Mirfin hit a post in extra-time.
But in truth these two sides could have played all night without finding the net.
Scunthorpe should have opened the scoring after 20 minutes when Garry Thompson danced into the area, but he delayed his shot and allowed Miguel Llera to make a goal-saving tackle.
The Dons got their first decent sight of goal when Sam Baldock's fierce drive was parried by Murphy into the path of top-scorer Wilbraham, who could only divert the rebound wide.
After the break, Wilbraham was inches away from breaking the deadlock with a low first-time shot from Sam Baldock's chest down which just flew the wrong side of the post.
Dons defender Llera was nearly left red-faced with a back-header which fell well short of keeper Willy Gueret and let in United striker Paul Hayes, who prodded his shot narrowly wide.
Hayes then got on the end of a long Murphy clearance but his attempted header over Gueret landed in the keeper's arms.
Moments later Wilbraham missed the chance of the game after Carl Regan reached the byline and fizzed the ball across goal, only for the 17-goal striker to barely make contact from two yards out as the opportunity went begging.
Substitute Luke Chadwick passed up a chance to go down in MK Dons' brief history when he headed wide in stoppage time.
Iron came closest to winning it in extra time with sub Jonathan Forte firing wide and Mirfin deflecting an attempted clearance onto a post.
And when the inevitable penalties arrived, Scunthorpe skipper Cliff Byrne fired over only for Jason Puncheon to be denied by Murphy.
Matt Sparrow then hit the crossbar but Jude Stirling, given the chance to win it, fired straight at Murphy.
Lee Morris held his nerve for Scunthorpe and 35-year-old Flo blasted his effort against the bar to send the visitors through.
