A tight match opened up late on, with Matt Macey twice called upon in the dying moments, while substitute Ronan Curtis had two great chances.
But Colby Bishop should have settled it two minutes from time, over to shoot over from eight yards with just Carl Rushworth to beat.
Some encouraging displays, however, and here are our on-the-whistle player ratings...
13. Portsmouth forward Colby Bishop (9) during the EFL Sky Bet League 1 match between Lincoln City and Portsmouth at Sincil Bank, Lincoln, United Kingdom on 27 April 2024.
Pompey's Colby Bishop fires in a shot in the first half against Lincoln. Picture: Jason Brown/ProSportsImages Photo: Jason Brown
14. Owen Moxon - 6
(Replaced Tom Lowery on 59 mins) Another good display as he continues to impress since his arrival. Puts himself about but also effective on the ball. Photo: Jason Brown
15. Christian Saydee - 6
(Replaced Callum Lang on 65 mins) Powerful, a handful, always great to watch him in full flow. Photo: Jason Brown
16. Abu Kamara - 7
(Replaced Tino Anjorin on 65 mins) If it is his Pompey farewell, what a loan it has been. Hit the post in stoppage time, converted by Lane to make it 2-0. Photo: Jason Brown