A five-star display at Upton Park got Hammers back to winning ways and pushed them up to third place in the Nationwide First Division.
Star of the show was Matthew Etherington, returning after a one-match suspension, who grabbed a stunning hat-trick and created another for former Wimbledon star Nigel Reo-Coker, while Bobby Zamora also netted a cracking goal against the doomed Dons.
It was the perfect response from Alan Pardew's men after Saturday's disappointing 0-0 draw with another struggling side, Walsall, when the pace and creativity of Etherington was sorely missed.
His return tonight allowed the Hammers boss to revert to a favoured 4-4-2 formation, although there was one other change in personnel, with Hayden Mullins failing to recover from the back injury he picked up at the weekend, meaning that Andy Melville came in for his full home debut.
After a nervy opening half hour, in which the young and eager visiting side defended stoutly and showed impressive energy to keep Hammers at bay, it began to look as though the Upton Park faithful could be in for another frustrating encounter.
However, as the Dons' early enthusiasm began to wane, the hosts' superior quality and fitness shone through and the breakthrough finally arrived nine minutes before the break.
Reo-Coker held the ball up well in the penalty area and laid off a neat pass for Harewood, whose dangerous low cross missed out Zamora but was slotted home at the far post by Etherington for only his second goal of the season.
Two minutes later, the lead was doubled. Zamora collected possession wide on the right and cut inside before unleashing a blistering effort from the edge of the area that whistled past former Hammers keeper Steve Banks into the far corner of the net.
That double-whammy clearly deflated the men from Milton Keynes and, as the two teams walked off at the interval, it seemed a question of how many would Hammers be able to add to their tally in the second half?
It should have been three just a minute after play restarted, when Harewood unselfishly fed Zamora, whose shot was tipped round the post by Banks but, moments later that miss was forgotten, as Hammers did grab the third.
Michael Carrick's measured pass dropped perfectly into the path of Etherington, who skipped away from his marker and slotted calmly past Banks for his second of the night.
15 minutes later, it was four, as Etherington generously turned provider and released Reo-Coker with an inch-perfect pass that allowed the former Dons captain to fire home his first goal in a Hammers shirt since his arrival in January.
The midfielder's muted celebration added even more poignancy to the moment, as he sheepishly accepted his team-mates' congratulations after hammering another nail into the First Division coffin of his previous club.
With the result safe, Pardew gave a rest to Zamora, Carrick and Jon Harley, but the sight of substitutes Jobi McAnuff and Adam Nowland joining Reo-Coker and David Connolly on the pitch made it almost unbearable for beleagured Dons boss Stuart Murdoch, as he watched his old charges surge forward in the hunt for more goals.
Connolly created the fifth in the 70th minute, slipping a pass behind the full-back for Etherington to race into the area and clip the ball over the advancing Banks for the first hat-trick of his career.
Perhaps the only surprise was that Hammers failed to add to their tally in the closing stages. Most frustrated was Connolly, who twice saw Banks deny him from close range and was then denied a last-minute strike by the linesman's offside flag, while strike-partner Marlon Harewood also wasted a glorious chance to get on the scoresheet when he volleyed over late on.
Still, it will have been the competent and ruthless team performance that will have pleased Pardew and his troops the most - the perfect tonic ahead of a tough trip to Sunderland's Stadium of Light on Saturday.