Three successive corners whipped over by Peter Hawkins allowed Neil Shipperley to nodhome his tenth goal of the season in the 19th minute.
In that opening period Rotherham failed to get a shot on target although a combinationof Wimbledon's inability to clear their lines and United's failure to capitalise on theirpressure was poor fare for the few that bothered to watch.
The second quarter, despite the goal, was even less entertaining and the half wounddown with both sides feet off the pedals.
On the hour disaster struck for United's captain Martin McIntosh. He rolled the ball backtoo hard beyond Michael Pollitt. This allowed David Connolly to chase the loose ball and ashe angled the ball home United's Nick Daws collided with the post and injured himself.
There then followed a busy period for both sides, but that bad error on the hour had allbut destroyed Rotherham.
Jobi McAnuff's running and shot failed to stretch their lead, before a more committed last15 minutes saw McAnuff clear an Alan Lee effort after the Wimbledon substitute PatrickAgyemang had headed over.
More Dons corners followed but it was Rotherham's Lee who got on the scoresheet. Acorner on the left was half cleared and when it came back in Lee, unchallenged, headedthe ball into the net and gave the Millers hope.
But the home goalkeeper Kelvin Davis had little more to contend with and the defencefought off a spirited Rotherham side.
The win was good news for Stuart Murdoch, because his Dons side had suffered threedraws on the trot previously