Liam Dickinson's goalscoring start to the season earned him a place in the starting eleven.
Anthony Elding moved to the left with Adam Griffin dropping to the bench.
And it was Elding who broke the deadlock when he powerfully headed home David Poole's cross from the right aft 13 minutes to send the Cheadle End into raptures.
It was no more than County deserved at that stage after laying siege on the Millers goal.
Matty McNeil might have scored twice in the opening seven minutes and Dickinson missed a great opportunity when Gary Dicker played him clear. Andy Warrington, though, made a good save.
Jim Gannon had predicted the Millers would be in the promotion shake-up at the end of the season and they slowly got back into the game.
Stephen Brogan was off target with a long-range effort on 24 minutes.
And the visitors came even closer on 37 when Derek Holmes climbed high at the far post to power a header just wide.
Half time: County 1 Rotherham 0
Dickinson and Poole, who both picked up knocks in the first half didn't reappear after the break. Adam Proudlock and Griffin were their replacements.
Two minutes after the re-start the dangerous Derek Holmes brought a great save out of Conrad Logan who dived full length to turn his 20-yard drive round the post.
The visitors levelled on 54 minutes when Ian Sharps headed home Brogan's free kick.
The County players reacted furiously as the referee hadn't whistled but the goal stood. Gannon continued the protests from the touchline and was sent to the stands by Mr Swarbrick.
Against the run of play the Hatters regained the lead on 68 minutes when Griffin stooped at the far post to head home Proudlock's corner.
Four minutes later, though, the Millers were level when McNeil spectacularly headed another Brogan free kick past his own goalkeeper.
Derek Holmes then came close with a volley that dipped just over.
But, with nine minutes remaining, County thought they'd won it when Elding headed Smith's cross over Warrington but the ball bounced to safety off the foot of the posy.
In an exiting end-to-end game Marcus Bean almost nicked it for the visitors when he got on the end of Bean's cross but shot just wide at the near post.
Pics courtesy of Graham Moore Grundy
