Matt Crooks' 10th goal of the season cemented Rotherham's position on top of Sky Bet League One as they triumphed 1-0 at Lincoln City.
Crooks headed home Kyle Vassell's cross in the 47th minute to secure the three points against a spirited Imps side at a sold out Sincil Bank.
After Jorge Grant curled a free-kick wide early on for Lincoln, Rotherham's only concerted attack of the first half saw Chiedozie Ogbene have a shot charged down by Jason Shackell and then his follow-up by Max Melbourne.
Grant was then denied by a brilliant one-handed save by Daniel Iversen as he headed Harry Anderson's cross goalwards.
Jake Hesketh then raced on to a lovely Liam Bridcutt - making his debut for the Imps - through ball to cross for the onrushing Anderson, who blazed wildly over the bar from six yards.
Within two minutes of the restart Rotherham took the lead. Dan Barlaser fed a ball out wide for Vassell, whose cross was headed home by Crooks past the despairing dive of Josh Vickers.
Imps goalkeeper Vickers kept City in the match after beating away a Vassell drive, before pouncing on another Crooks header.
Tyreece John-Jules almost scored the equaliser, but could not get enough power on his effort from sub Anthony Scully's cross and Richard Wood was able to hack clear a yard off his own goalline.
Scully and John-Jules combined again with the latter's low shot saved by Iversen's leg in the final minute.