They went close three times within the first five minutes, twice through Alex Revell and then Lewis Grabban shooting just wide.
And Rotherham led in the eighth minute. Marcus Marshall's cross evaded everyone in the penalty box and as the ball bounced free Gareth Evans fired home a the far post.
But the home side were pegged back in the 21st minute when slack marking in the Rotherham defence allowed Scott Doe to head home Gavin Tomlin's corner.
However two goals in nine minutes from Grabban put Rotherham back in the driving seat. After 29 minutes he flicked home from Marhsall's high right wing cross and nine minutes later he reaped the reward for some great work by Evans.
Evans robbed Tomlin out left and crossed for Grabban to spin and shoot past Chris Lewington into the corner..
Two half time substitutions put more life into the visitors after the break and Oliver Lee twice went close, first hitting the bar and then having a shot well saved by Conrad Logan. Then Doe directed a header just wide.
At the other end Dale Tonge rattled the bar with a fierce drive then Grabban was denied a hat trick when Lewington Palmed his 78th minute free kick over the bar.
Source: DSG