The Blues sealed the three points after edging a second half that produced five goals.
George Hirst (50 minutes – penalty) and Michael Jacobs (68) handed the home side a 2-0 lead, before Teddy Bishop (70) and substitute Ben House (78) got the Imps back on level terms.
However, Pompey substitute Ronan Curtis restored the Blues’ advantage on 82 minutes when he made the most of goalkeeper Jordan Wright’s inability to hang on to Sean Raggett’s drilled effort to bag his eighth goal of the season.
5. Connor Ogilvie - 7
Always ready with a full-blooded tackle, while willing to help out the left flank. Photo: JPIMedia
6. Marcus Harness - 7
Worked hard, regularly tracking back, and always a threat in attacking positions. Photo: JPIMedia
7. Joe Morrell - 6
(Replaced by Ryan Tunnicliffe on 12 minutes): Early injury ended his participation. Photo: JPIMedia
8. Louis Thompson - 6
(Replaced by Shaun Williams on 71 minutes): Looked sluggish in first half and eventually taken off with injury issue. Photo: JPIMedia