Andy Warrington had to be in fine form to deny Stanley after Rotherham, looking nervous and a touch tentative after being made one of the favourites for promotion, made a sluggish start.
The veteran made two stops in the first 20 minutes, denying Jimmy Ryan from a free kick and then getting down low to hold Paul Mullin's shot from just outside the area.
There was little to shout about for Rotherham as new boy Tom pope was closely marshalled and strike partner Ryan Taylor creating little, and it was Warrington called into action again before the break as he flew to his right to palm Rob Grant's powerful 25 yard effort for a corner.
After the break, and the introduction of 36 year-old Warne, the Millers found their gears a little after survivng yet again as Pablo Mills dwelled on the ball to let in Ryan agin on 48 minutes but Warrington narrowed the angle to beat his shot away from danger.
On 52 minutes The Millers saw their best effort cleared off the line, as Nick Fenton rose to meet Nicky Law's corner but saw his header thumped away by Luke Joyce.
Warne's shot from Ellison's flick into his path on the hour was beaten away by 'keeper Martin before Ian Shaprs, and then Pablo Mills in particular, both missed golden chances to get on the scoresheet - Mills heading wide unmarked from eight yeards out.
But with a minute left Warne pounced to crash in the winner after Sharps had hit the bar then reacted quickest to the loose ball to tee him up.