The Imps battled to a valuable point to further extend the gap between them and the bottom four.
City threatened straight from the kick-off after Maguire clipped a ball out to Brooke Norton-Cuffy, whose cross was collected by Anthony Patterson under pressure from John Marquis.
The play-off chasing visitors were full of confidence and enjoyed a good spell, with Patrick Roberts particularly impressive - and only just failing to get on the end of a left-wing cross from Jack Clarke.
Luke O'Nien also headed over for the visitors, as did Clarke.
City saw out the early pressure and began to create opportunities of their own, with Lewis Fiorini having a shot blocked after 14 minutes before a well-worked free-kick results in Norton-Cuffy putting in a dangerous cross which needed a perfectly-timed interception by Dennis Cirkin to concede a corner rather than a goalscoring chance.
Fiorini almost set Marquis through on goal after 24 minutes, with Corry Evans timing his tackle brilliantly to stop him getting away.
Clarke was twice gifted opportunities to shoot after slips by Imps players, but on both occasions he sent his effort low and wide of the post.
Goalscoring chances dried up as the half drew to a close, with Wright out quickly to deny Stewart a shooting opportunity with five minutes to go.
City ended the half strongly with a number of corners and Hopper flicking a Marquis cross just wide.
There was no change from either side at the interval, with Corry Evans going close to opening the scoring after 56 minutes when he clipped the far post after Roberts' pull-back.
And Clarke will have felt he should have done better for the visitors after 62 minutes when he tried to place a smart finish into the bottom far corner but sent his effort wide.
City made their first change after 65 minutes, bringing on Morgan Whittaker for Joe Walsh.
That helped the Imps gain an attacking impetus, with Hopper almost getting on the end of a Norton-Cuffy cross and Patterson having to be alert to pluck Whittaker's cross out of the air.
Sunderland boss Alex Neil sent on Leon Dajaku and Jermain Defoe as he tried to regain the initiative, with the latter flashing an effort low and wide with just over 10 minutes to go.
Adam Jackson sent a header over from Maguire's cross as the Imps created the best chances in an open finish to the game.
Whittaker's twisting run won a corner with several players waiting in the area, with Firkin getting a vital interception. That corner came to nothing as referee Craig Hicks gave a foul against City.
Moments later Cullen, who had only just entered the match as a replacement for Marquis, drew a fantastic save out of Patterson after Hopper's cross from the right. The Black Cats keeper just did
enough to tip the ball onto the woodwork.
And when the visitors did break though, Wright did well to stop Evans' shot from outside the area with two minutes to go. And, with the first of three minutes time added on played, Wright again did brilliantly with a diving save from Stewart's header
Attendance: 10,346 (2,081 away)
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