City's two goals ended a run of over 300 minutes without finding the net and the victory broke a run of three consecutive draws.
But Wrexham created chances early on before fading away.
Robbie Foy lost control in the box after just 11 minutes and then Jonathan Walters rose to meet a cross from Foy but saw his header saved by Lincoln keeper Alan Marriott.
But gradually Lincoln got on top with Derek Asamoah and Dean Keates both having first-half shots charged down.
Wrexham keeper Michael Ingham fumbled a 45th minute shot from Asamoah but no Lincoln player was near enough to take advantage.
The second half was all Lincoln and they went close in the 49th minute when a corner from Keates deflected off Nat Brown only to be blocked on the line.
But the breakthrough came in the 64th minute when Ingham dropped a corner from Scott Kerr. In the scramble that followed Brown forced the ball home from close range.
Lincoln went close again four minutes later when Kerr sent in a hopeful effort from 40 yards which brought a diving save from Ingham.
Wrexham found it difficult to control the lively Asamoah with both Alex Smith and Paul Warhurst yellow carded for fouling the striker.
Lincoln introduced substitute Francis Green for the final 15 minutes and he opened the game up.
Green was only on the pitch four minutes when he broke away down the right flank and cut in. He finished with a low shot which Ingham could only push away at his near post.
Six minutes from the end Paul Mayo ran at the Wrexham defence before setting up Gary Birch. The striker shot hurriedly and his effort went over the bar.
But Lincoln wrapped the game up in stoppage time. The veteran Warhurst was caught on the ball midway inside his own half. Green robbed him and then advanced into the Wrexham area before producing a neat cross which was tapped in by Keates for the midfielder's second goal of the season.