First-half goals from Ronan Curtis, either side of Ryan Jackson’s effort for the visitors, put Danny Cowley’s side 2-1 at the break.
Clark Robertson then added a third for the hosts nine minutes after the restart as Pompey remain ninth in the League One table.
5. Connor Ogilvie - 7
(Replaced by Mahlon Romeo on 78 minutes): Solid showing against his former club, yet forced to come off with injury. Photo: JPIMedia
6. Joe Morrell - 7
Covered so much ground and used ball very well. Photo: JPIMedia
7. Louis Thompson - 7
(Replaced by Jay Mingi on 74 minutes): Makes a difference when he starts for the Blues and again reminded us of his quality. Photo: JPIMedia
8. Marcus Harness - 7
(Replaced by Aiden O'Brien on 89 minutes): One of his good days and created opener for Ronan Curtis. Photo: JPIMedia