Michael Smith gave the Millers the lead midway through the first half, but Imps substitute Lewis Fiorini equalised 10 minutes after half time.
Lincoln had goalkeeper Josh Griffiths to thank, meanwhile, for making a series of excellent saves in the closing stages in addition to several squandered Rotherham chances.
After an even opening the first chance fell to the Millers in the 13th minute. Good work by Freddie Ladapo saw the ball pulled back for Smith, but he was denied by the feet of Griffiths.
Ten minutes later, however, the two combined again in similar fashion and this time Smith made no mistake inside the six-yard box from Ladapo’s centre.
Lincoln rallied after break and were soon level through Fiorini, who played one-twos with both Lasse Sorensen and Chris Maguire before striking under Viktor Johansson.
Lincoln were somewhat fortunate though to still have 11 men on the field when Adam Jackson was shown a yellow card after scything down Ollie Rathbone.
Smith went close to adding his second with 20 minutes to go, but Griffiths denied the striker with a fine reflex save.
It was all one-way traffic in the last 15 minutes with Griffiths expertly denying headers from Smith and Will Grigg, while the pair – and Ben Wiles – both fired further chances just wide.
Lincoln: Griffiths, Poole, Montsma, Jackson, Robson (Bramall 81), Bridcutt, McGrandles (Fiorini 22), Sorensen, Maguire (Adelakun 67), Hopper, Scully. Unused substitutes: Long, Bishop, Nlundulu, Eyoma.
Rotherham: Johansson, Mattock, Barlaser, Ladapo (Grigg 68), Ogbene, Bola (Sadlier 68), Lindsay (Wiles 81), Rathbone, Ihiekwe, Edmonds-Green, Smith. Unused substitutes: Vickers, Wood, Kayode, Odoffin.
Referee: S Barrott (West Riding).