City looked to have the game sewn up by half time after establishing a comfortable lead with the Quakers a player down.
But Darlington manager David Hodgson gambled by putting on an extra striker in place of a defender. The move paid off and in the end Darlington not only levelled things but could and should have won.
Lincoln went close after 9 minutes when Dean Keates put Jeff Hughes clear but the midfielder shot into the side netting.
The breakthrough came on 17 when a Scott Kerr corner was flicked on by Jamie McCombe. The Darlington defence could only watch as Gareth McAuley came in at the far post and blasted home from 6 yards.
Two minutes later Darlington conceded another from a set piece. A long throw from Paul Mayo was laid back by Richard Logan and Marvin Robinson forced the ball home.
Darlington's woes increased in first half stoppage time when striker Akpo Sodje floored Luke Foster with a late challenge which the ref decided was two footed and produced a red card. Darlington also had Simon Johnson booked in the following arguments.
At the break Darlington went for broke and switched to a 3-3-3 formation which Lincoln could not cope with. Within seconds Matt Clarke headed inches wide and Tresor Kandol got away but his shot was saved by Alan Marriott.
In the 55th minute Lincoln escaped when an overhead kick by Wainwright came back off the post. Darlington wasted two more chances before pulling one back on 63. Substitute Guylain Ndumbu-Nsungu put Kandol clear and although his shot came back off Marriott he retained his composure and put the rebound home from close in.
Darlington levelled things up 6 minutes later when Ndumbu-Nsungu turn McCombe inside the box and fired in.
Lincoln desperately looked for a winner with David Knight making a tremendous late double save to prevent Keates and Logan from finding the net.
In stoppage time Ndumbu-Nsungu found Logan with a great pass but his shot was deflected wide.