NIC McDonnell was the Lillywhites hero last night, heading the goal which puts Bromley within one win of promotion.
The prolific striker was the difference in a tension-filled match in front of more than 3,200 fans at Hayes Lane.
However, Bromley were helped immensely by the inexplicable behaviour of Wimbledon's Wes Daly who was sent off after half-an-hour for two yellow cards.
But McDonnell's 30th goal of the season means Bromley host Billericay in the play-off final this Saturday, kick off at 1.30pm.
Mark Goldberg made one change to the side which beat Boreham Wood at the weekend with Tony Boot replacing Garath McCleary.
The boss was still without Donal O'Sullivan and Barry Moore so Bobby Bowry Bowry and Junior Kadi continued to deputise.
Wimbledon started better. Andy Walker had to save well from Richard Jolly and Roscoe D'Sane should have at least hit the target with a free header from six yards.
Daly picked up his first card for a late challenge on Mark Corneille and 10 minutes later the same man pulled Boot back right in front of the referee, who he duly produced another card and dismissed the midfielder.
Inbetween, Boot and McDonnell combined well for Bromley's first sight of goal on 25 minutes but Andy Little was out smartly to deny Boot.
With five minutes of the half remaining, Sam Wood stretched his legs down the middle of the pitch but an untidy one-two with MCDonnell prevented Wood from geting a clean strike and his effort flashed over.
The final action of the half belonged to the visitors as Steve Ferguson somehow barged his way through for a strike but the ball went wide.
Bowry, who was clattered midway through the first half, was replaced with Jerrome Sobers at the break.
Bromley had the ball in the net on 46 minutes but Boot was adjudged to be offside as he scooped in a rebound.
Moments later Sobers was booked for a foul on Luke Garrard and for the rest of the game the defender walked a tightrope.
Wood's drive on 55 minutes only found the keeper's arms but his team were building up the pressure.
It told almost immediately when Wood and Gareth Williams combined to cross for McDonnell, who headed home emphatically at the near post to send the Bromley faithful behind the goal into delirium.
Lee O'Leary was booked for dissent in the aftermath as Wimbledon claimed a foul which never was.
Peter Adeniyi, Tutu Henriques and Boot all spurned half-chances as Wimbledon's numerical disadvantage began to tell.
However, the introduction of Chris Gell for Jermaine Darlington boosted the visitors and the substitute flashed a drive over Walker's bar.
Garath McCleary took over from Boot and the striker could have put the match beyond Wimbledon but he dallied when in on goal and the chance was gone.
McDonnell almost doubled his tally with a rasping volley off Adeniyi's cross but Little was equal to the effort with a splendid close-range save.
The game was always on the brink of boiling over but it did not quite get there despite the Dons trainer being sent to the stands and a booking for Francis Duku and D'Sane for a small session of handbags.
On 90 minutes the assistant referee's board showed a massive eight minutes of injury time and Wimbledon almnost took advantage.
Goldberg took off the struggling Corneille for Chris Sharpling and Wimbledon's last throw of the dice saw Stephen Goddard replace O'Leary.
From a Wimbledon corner D'Sane flashed the ball over the bar.
And the Bromley faithful had their hearts in their mouths on 96 minutes when a mix-up between Walker and Duku presented D'Sane with a lob which skimmed the crossbar as it trickled down the back of the net and out for a goal-kick.
From the restart the referee blew full time and the celebrations began - now they have to do it all over again on Saturday.
Previous match 
