Bryan Hughes moved out of the shadows to mastermind Birmingham City's progress into the fifth round of the FA Cup for the first time in seven years.
Hughes grabbed the vital goal in the third minute of the game in the Blues' first attack on Wimbledon's goal.
It was a crucial strike in a game Birmingham had been expected to win in a canter.
But this never materialised as the young Wimbledon side blossomed against their Premier League opposition to produce a performance which, on the overall play, deserved a second chance.
Birmingham City, who have never won the FA Cup, were relieved to have won against such tenacious opponents.
Rock-bottom of the Nationwide Division One table, Wimbledon, can take heart from their performance which was full of promise.
Their manager, Stuart Murdoch, said he was very proud of his players.
"They played well after a difficult week," he said.
"They showed great character, great determination and great spirit.
"Morale was at its lowest point early in the week but they picked themselves up and were very keen to do well.
"I could not ask more of them except to score a goal. To say we were playing against a top ten Premier League side we can take a lot of credit for our display today." In the absence of manager Steve Bruce "on other business" coach Mark Bowen admitted: "It was a case of after the Lord Mayor's show following a fine performance at Chelsea.
"We didn't get at them after scoring an early goal. But give credit to their manager who prepared his Wimbledon side well for this cup tie.
"But all that matters is that we are in the fifth round of the Cup and no one will be bothered about this performance if we can progress even further in the competition.
"I thought Bryan Hughes was our man of the match. We worked tirelessly and deserved the goal he scored." Unfortunately Wimbledon are a club who are rapidly dropping back to their roots due to a number of situations which have proved to be a dragging chain on any aspirations.
The down side of being in administration and forced to sell yet another two of their most promising young players, Nigel Reo-Coker and Adam Nowland, to West Ham United only days before meeting Birmingham, highlighted their problems which were exacerbated in this cup tie.
In the circumstances it is hardly surprising that Murdoch, who didn't even know of the impending transfers of Reo-Coker and Nowland, has such a monumental task as he tries to keep Wimbledon afloat.
But it is a losing battle and Birmingham surprisingly failed to take advantage of Wimbledon's plight and had to work hard for their narrow success.
The Dons may be young and obviously inexperienced but they nevertheless battled bravely to combat a Birmingham side that is currently enjoying some of the success Wimbledon experienced during their rapid rise from obscurity into the old First Division a few years ago.
They hardly performed like a team in free-fall and rapidly losing touch with other teams at the bottom of the First Division.
But they could not have made a worse start as they found themselves a goal down after only three minutes when Hughes scored from what appeared to be a blatant offside position.
The move began harmlessly enough in midfield when Robbie Savage put David Dunn in possession. The former Blackburn player veered to the right to give a short pass to Stern John.
John, who retained his position in preference to Mikael Forssell, cleverly worked his way inside and nudged the ball to Clinton Morrison who switched a pass into the path of Hughes to nonchalantly put his low shot past goalkeeper Steve Banks.
Ironically, a minute before, Hughes was told off in no uncertain terms by Darren Purse after he had turned a dangerous cross back towards his own goal from short range.
The spirit of the Wimbledon side was highlighted in the 19th minute when a Purse slip let in Dean Lewington. He set up young Jamie Mackie who saw his shot hit the post as he was challenged by Maik Taylor.
Taylor came to Birmingham's rescue a minute later when he was forced to desperately push a Lewington free-kick around the post.
An equally fine save by Banks kept out a speculative attempt from Dunn as Birmingham went in search of a decisive second goal.
Banks was again in brilliant form when Morrison clawed the ball from Mikele Leigertwood and attempted to guide his shot home only to see the Dons keeper turn the attempt around the post.
Wimbledon's danger on the break could never be underestimated as was again demonstrated when Dunn made a mistake which put Mackie in possession.
He swiftly found Wade Small who beat Taylor from 25 yards only for the ball to go just wide of the far post.
In the situation which developed Birmingham became increasingly frustrated by their inability to completely dominate the Dons.
They struggled for a second goal and Wimbledon were able to compete against a Birmingham side which struggled to get into top gear.
There was an anxious moment for Wimbledon five minutes into the second half when Hughes was brought down in the area by Jermaine Darlington but referee Uriah Rennie did not see any offence.
Veteran Dean Holdsworth played his part in attack but it was Wimbledon's youthful mobility which enabled them to keep the tie wide open.
Rob Gier, Darlington and Leigertwood all performed heroics keeping Birmingham at bay for long spells, while Wimbledon's young skipper, Joel McAnuff, impressed with a non-stop assault on the home defence.
The return of Robbie Savage and Dunn to midfield failed to give Birmingham any real advantage against the live-wire Wimbledon players.
Dunn was the first player to be substituted when he was replaced by Forssell in the 64th minute.
Man of the match. Bryan Hughes (Birmingham City) scored the only goal and impressed with a consistent and assured display.