Joe Pigott scored twice after having an early penalty saved by Ryan Allsop to condemn the Chairboys to defeat, though results elsewhere have all but secured Wanderers' place in League 1.
Allsop made amends for conceding the penalty by keeping out Pigott's spot-kick but the striker did break the deadlock, heading home a corner.
Alex Samuel levelled the scores with a near-post finish before Pigott headed home the winner, with Wimbledon holding on to their lead despite some late Wanderers pressure.
Wycombe will be safe from relegation unless they lose next Saturday and suffer a drastic swing in goal difference with Plymouth and Southend both winning their games.
Gareth Ainsworth was forced into one change to his side, with Sido Jombati missing out with a broken foot, prompting Anthony Stewart’s return to the team.
The hosts started assertively, looking to involve striker Joe Pigott in every move, and he helped win an early corner which was headed over the bar by James Hanson, arriving late at the back post.
And Hanson was then involved in a major talking point, racing onto a through-ball and poking it past the onrushing Ryan Allsop, who brought him down in the challenge. The referee wasted no time in pointing to the spot, and –after a delay for treatment – showed a yellow card to the keeper. Wimbledon fans were baying for a red card, and were more incensed to see Allsop make a superb save from the penalty, guessing the right way to deny Pigott.
It needed to serve as a wake-up call for the Blues, who’d yet to get going in the game, and they improved with a fast counter-attack down the right which culminated in Nick Freeman’s teasing dinked cross being well defended just ahead of Adebayo Akinfenwa.
Then Adam El-Abd hit the post with a header from Jason McCarthy’s corner following excellent work from Alex Samuel down the left, before McCarthy’s dangerous free-kick was well tipped over by keeper Aaron Ramsdale.
Half-chances arrived for Scott Kashket and Dominic Gape, either side of a free-kick from Anthony Wordsworth which landed kindly in Allsop’s arms, before Wimbledon took the lead, with Pigott atoning for his earlier miss with a routine header from an inswinging corner.
Wycombe all of a sudden could have been 2-0 down when James Hanson was freed down the middle but, with El-Abd for company, took his shot early and Allsop stood firm to beat it away.
1-0 was how it stood at half-time, but Wanderers came out with renewed vigour in the second period and earned their equaliser, given to them by Alex Samuel on 49 minutes. Steve Seddon lost his footing at a vital moment in the Wycombe penalty box with a golden chance to make it 2-0, but the visitors broke and when McCarthy crossed to the near post, Samuel was on hand to bundle home.
It was so nearly 2-1 to Wycombe moments later, with Samuel again at the heart of it. Scott Kashket worked wonders down the right to fashion a crossing opportunity, and his delivery was perfect for Samuel to soar above his man but send his header crashing against the woodwork.
And they were made to pay moments later, when Pigott restored Wimbledon’s advantage. A cross from the left hung in the air after challenges from players of both sides but it fell kindly for Pigott to nod past Allsop from close range.
The visitors’ response was strong, with Wimbledon beginning to sit deeper and invite the pressure, though they did enough to deny clear-cut chances, with Nick Freeman trying his luck with a snapshot from distance which was beaten behind by the keeper.
Curtis Thompson and Samuel both drilled straight at the keeper from the edge of the box, while Wanderers made their first change, introducing Nathan Tyson for Scott Kashket.
Wimbledon made a double change on 78 minutes, bringing off Pigott and the injured Paul Kalambayi as Tennai Watson and Dylan Connolly took their place. Further subs arrived with Matt Bloomfield and Paris Cowan-Hall entering the fray, but the Dons were showing enough resilience to keep the Blues at bay despite late pressure.
Results elsewhere mean Wanderers sit three points clear of the drop with significantly superior goal difference, suggesting that survival will be officially clinched on the final day at home to Fleetwood.