On-loan striker Ashley Grimes gave Lincoln the lead after 10 minutes when he forced his way through three tackles before netting with a low shot.
And Grimes, who has revived his career since his move from Millwall, was on the scoresheet again in the 42nd minute.
He turned a defender inside the box before firing home off the post for his 11th goal in just 14 starts for Lincoln.
Lincoln's veteran striker Delroy Facey was then narrowly off target with a long range effort.
Morecambe, now without a win in six games, created chances in the second half but were denied by some outstanding saves from Lincoln keeper Trevor Carson.