Alex Revell's header earned Rotherham victory over in-form AFC Wimbledon and moved them to within two points of the League Two automatic promotion places.
Revell netted after Kari Arnason flicked on Lionel Ainsworth's corner to earn a first win in four games.
The Millers dominated against a massed defence and keeper John Sullivan denied Lee Frecklington and Claude Davis while Johnny Mullins also went close.
Harry Pell had the away side's best chance after half-time.
But Rotherham fully deserved their win against a side who had won four of their last five games to steer away from relegation trouble.
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Rotherham United manager Steve Evans told BBC Radio Sheffield:
"We've watched game after game here, where if it was a boxing match they'd throw in the towel in.
"It would be stopped because we had so much possession, so much domination.
"We said to the players at half-time if we end up drawing nil nil, but trying to still play the right way, then we'll live with it.
"But we're delighted obviously to get three points."