STUART Beavon was the late hero as his stoppage time header earned a hard-fought point for Wanderers.
The striker pounced to steer a header into the back of the net to keep Wycombe's unbeaten run going and to take his own tally to eight goals in six games.
It was a deserved point for Blues but looked likely to evade them after Daniel Powell put MK Dons ahead minutes into the second-half.
And they also had goalkeeper Nikki Bull to thank after his 10 th minute penalty save – his third in a row – to deny Jay O'Shea.
A run of one defeat in their last six games had renewed confidence at Adams Park.
Fears that confidence would be shaken came when on-loan striker Paul Hayes, who had netted six in six for Wanderers, was recalled by the Addicks yesterday.
And again when captain Dave Winfield failed to shrug off a thigh strain and Matt Bloomfield ruled out with a calf injury.
But Wycombe thrived on the derby challenge against high-flying Dons but needed Bull's heroics to set up a stirring first-half performance.
The Blues stopper was called into action after 10 minutes after full-back Marvin McCoy bundled ex-Manchester United midfielder Alan Smith over in the box.
Up stepped O'Shea but Bull kept his incredible run going by foiling the striker with a double save from the spot.
It was a moment that seemed to inspire Wycombe, who created the best of the chances that followed with Stuart Lewis screwing a shot wide, Ben Strevens heading over and Stuart Beavon blazing a shot past the post.
MK Dons had been a shadow of the side chasing down an automatic promotion spot so successfully.
But with 93 goals this season it seemed unlikely Wycombe would become only the fourth side to keep them out this season.
And so it proved.
The Dons punished them for not making the most of their first-half dominance when Powell fired them in front to net the 300 th goal in games involving the two sides this season.
It relaxed the Dons who threatened to extend their lead with Mathias Doumbe volleying wide from a tight angle.
Wycombe continued to compete well against their prolific neighbours, who flexed their muscles by bringing Dean Bowditch and Jabo Ibehre off the bench in the second-half.
But creating clear-cut chances proved difficult for Wanderers with Strevens sending a header over the bar after Gary Doherty helped on a corner.
Wycombe threw the kitchen sink at MK Dons in the final stages and visiting boss Karl Robinson, celebrating becoming the first boss to reach 100 games in charge, who craved the final whistle.
But he had to settle for a point when Beavon rose to glance his header into the back of the net to bag a crucial point for Wanderers.
WANDERERS: Bull, McCoy, Laing, Doherty, Basey, Hackett (Ainsworth 63), Lewis, Eastmond, McNamee (McClure 61), Strevens, Beavon.
Subs (not used): Stewart, Scowen, Dunne.
Booked: Basey (17 mins).
MK DONS: Martin, Smith (Ibehre 78), Doumbe, Flanagan, Lewington, Powell, Gleeson, Potter, Williams, O'Shea (Bowditch 63), MacDonald (Chadwick 90).
Subs (not used): McLoughlin, Hall.
Booked: Smith (32 mins).