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.
9. Michael Jacobs - 8
Another assist from a corner and play on the ball at times a delight. Photo: JPIMedia
10. Ronan Curtis - 8
Back in his favoured left-wing role and marked welcome return to the position with two goals. Photo: JPIMedia
11. George Hirst - 8
Held ball up superbly throughout and a constant threat. Photo: The News
12. Jay Mingi - 6
(Replaced Louis Thompson on 74 minutes): Good to see him given an opportunity. Photo: JPIMedia