MK Dons beat Mansfield 1-0 at Stadium MK to leapfrog the Stags and claim the third and final automatic promotion place in League Two.
The game had been billed as a winner-takes-all contest in the build-up, and it was Paul Tisdale's side who took the lead inside 120 seconds when David Wheeler headed home a corner from long-serving skipper Dean Lewington.
The Stags - who were forced into two first-half changes - gave a fantastic account of themselves, with Danny Rose testing MK Dons goalkeeper Lee Nicholls on a number of occasions, but the resolute backline of the hosts held firm, despite a late onslaught.
League Two play-off schedule
|Thursday 9 May||19:45||1st Leg||Newport vs Mansfield|
|Friday 10 May||19:45||1st Leg||Tranmere vs Forest Green|
|Sunday 12 May||18:00||2nd Leg||Mansfield vs Newport|
|Monday 13 May||19:45||2nd Leg||Forest Green vs Tranmere|
MK Dons return to League One after taking the final automatic promotion spot, while David Flitcroft's Mansfield side must now face Newport County in the League Two play-off semi-finals.
The home side took the lead after just two minutes when Lewington's corner was met by Wheeler unmarked inside the Mansfield box, before the QPR loanee headed emphatically past Mansfield 'keeper Conrad Logan - his fourth Dons goal of the season
Tisdale's side should have doubled their lead midway through the first half when Kieran Agard's cut-back across the six-yard box found Chuks Aneke, whose first-time effort was cleared off the line by Stags defender Ben Turner.
Logan made a superb save to deny MK frontman Agard in the 66th minute to keep the Stags in it, before Flitcroft's side were themselves denied when Russell Martin cleared Jorge Grant's deflected cross off the line to keep things at 1-0.
Despite the Stags throwing bodies forward late on, they could not find a way through a brilliant Dons defensive display.
Tisdale hails his heroes
Paul Tisdale believes MK Dons' promotion back to League One was payback for the supporters who have stuck with the club through their dark days.
"I have tried to harness the bad couple of years the club has had, so today has given us redemption and given something back to the supporters," he said.
"I asked the players to stay here in the summer and not to run away from the club that has supported you and the fans who have given their all - I'm so pleased we are able to celebrate this moment together today.
"Players like Kieran Agard and Chuks Aneke, who played so hard today, could have easily left in the summer after last season's relegation.
"I have spent all week telling the players not to plan any celebrations because you cannot dream until you have done the job - it is the worst thing you can do.
"My backroom staff and I spend a lot of time together and under pressure you have to know who is around you and who you can lean on. They have followed me here and I must thank them because they have all committed - the team behind the team have been brilliant.
"I have said to the players all season that they have to write their own story this year. We have started off nicely here and we now have a good platform, it is a contemporary football club which I like and hopefully now we have a nice springboard to move it forward."