Reds suffered their first League defeat of the season after a late goal from David Worrall sealed a winning return to the Broadfield for Steve Evans.
Richie Barker made one change to the side that had shared six goals with Tranmere a week ago as Kyle McFadzean came in for Joe Walsh, who had a tight hamstring.
The visitors started strongly and Paul Jones had to push away an early shot from Ben Pringle but the hosts gradually got back into the game and went in front on 13 minutes.
A training-ground routine saw Mat SADLER swing in a free kick which picked up pace off the pitch and went past Scott Shearer and inside the right-hand post.
Sadler was in action again at the other end 11 minutes later when he headed a half-volley from Michael O’Connor off the line as the visitors continued to offer an attacking threat.
Nicky Adams’ trickery was a good outlet throughout for the home side and Jamie Proctor met his cross to head just over as play flowed from end to end.
But Rotherham were always a threat. Alex Revell headed the dangerous Pringle’s cross just wide and on 37 minutes it was 1-1. Pringle was again the creator when his corner was headed back across goal by Kari Arnason and Kieran AGARD stooped to head home.
Both sides went close again before the break. Shearer saved a shot from Adams and at the other end Paul Jones reacted smartly to tip over a header from Revell.
Little had been seen of Matt Tubbs on his return to the Broadfield but he headed over from Mark Bradley’s deep centre at the start of the second half.
Shearer made a comfortable save from Proctor’s shot then on the hour Lee Frecklington struck a half-volley from 20 yards which flew just wide.
Reds made a couple of changes with Gary Alexander and Luke Rooney both coming on and with 15 minutes to go the game had fizzled out a little and looked like heading for a draw.
But on 76 minutes Reds failed to clear a cross and David WORRALL, who had come off the bench, hit a sweet half volley just inside the right-hand post. Not for the first time this season Reds had been punished for failing to defend diligently.
The hosts tried to mount a late response and Josh Simpson was a whisker away from prodding in Alexander’s cross on the turn, but the Millers headed home with their first league win since promotion under their belts.