Luke Varney’s late winner secured Ipswich’s first win in eight games, despite Alex Revell’s brace for already-relegated MK Dons.
David McGoldrick volleyed in his first goal since August to put Ipswich ahead.
Revell, who recently saved a penalty as an emergency goalkeeper against Preston, levelled from the spot.
Brett Pitman’s glancing header restored Ipswich’s lead, and Revell poked home Josh Murphy’s free-kick to equalise before Varney’s header sealed victory.
Ipswich manager Mick McCarthy: “It was exciting for both sets of fans but frustrating for me.
“We have already started thinking about next season – that is an ongoing process.”
MK Dons manager Karl Robinson: “It was disappointing for us but it summed up our whole season. We were good but also poor in certain key areas.
“It has been a massive learning curve. Some of these players deserve to be in the Championship but some don’t and that is why we are where we are.”