Loan signing Sam Wood made his Millers debut as a replacement for winger Gareth Evans who has been ruled out for a month with damaged ankle ligaments. Defender Guy Branston was named a substitute after coming back from suspension but there was no place for fit-again Michael Raynes.
Millers took the lead after 20 minutes. Brett Williams finding the target after good work from Alex Revell.
The visitors equalised three minutes after the restart when Tyrone Barnett fired home.
And it got worse for Rotherham on 68 minutes when Josh Simpson put the visitors in front for the first time.
For reaction and big-match report from today’s game, read Sports Monday, free with Monday’s Yorkshire Post newspaper.