The Millers, who move into their purpose-built New York Stadium in time for next season, had only one goal to show for a game they dominated and paid the price when Adebayo Akinfenwa headed home an injury-time equaliser.
It could have been so different, with leading marksman Lewis Grabban hitting the post, having a goal disallowed for offside and then seeing a 30-yard drive tipped over the crossbar.
Grabban also had a hand in the goal, providing the cross for Alex Revell to fire home in the 31st minute.
The visitors struggled to match Rotherham going forward and their one effort on target was a Toni Silva shot in the eighth minute, which goalkeeper Rhys Taylor saved comfortably.
Rotherham could not improve on their advantage as Ben Pringle's 25-yard drive whistled just over the crossbar and Grabban fired into the side netting, and the visitors stole a point when Akinfenwa headed home Luke Gutteridge's free-kick in stoppage time.