Christian Jolley struck five minutes into injury-time as AFC Wimbledon beat Port Vale to earn their history-making first home win in the Football League.
Jack Midson opened the scoring, slotting home the rebound after Stuart Tomlinson saved Luke Moore's penalty.
Louis Dodds curled home a leveller from the corner of the box but Dons' Gareth Gwillim fired home from 25 yards out.
Vale's Sam Morsy levelled on 84 minutes from close range before Jolley won it, bending a shot into the bottom corner.
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AFC Wimbledon boss Terry Brown told BBC London 94.9:
"We couldn't have done it any harder, but credit to Port Vale, they totally dominated the first half and I don't know how we went in winning at half-time.
"If they'd taken their chances then they'd have been out of sight.
"Credit to Christian Jolley and Jack Midson who ran their socks off for us up front, and I was really really proud of my players who showed a great deal of character and resilience."
Port Vale boss Micky Adams told BBC Radio Stoke:
"I can't quite believe we've lost, especially with the amount of chances we've created.
"It's quite criminal. The game should have been finished at half time, so when we came in we felt a little bit mugged.
"We're devastated, but that's football. Good luck to Wimbledon - I think they'll feel slightly fortunate tonight, but let's hope it evens itself out over the season."