The Blues started poorly and were fortunate to get to half-time goalless, with the visitors hitting the post and wasting several great opportunities.
However, they stepped up their game considerably after the break, with man-of-the-match Colby Bishop scoring twice in five minutes to secure a 2-0 victory.
And here are our Pompey player ratings...
9. Paddy Lane - 7
(Replaced by Gavin Whyte on 70 mins) Tried to get Pompey going in that insipid first half so deserves credit for that. Remained bright on the right flank and posed more of a threat than Kamara on the left. When he gets the ball always suggests something could happen. Photo: Jason Brown
10. Colby Bishop - 9
Attacking masterclass from the leading scorer. Led the line magnificently in the first half as many of his team-mates struggled to spark, particularly in a tough ongoing battle with Nathan Smith. Then popped up when the Blues needed him most to deliver victory. Now on eight goals for the season. Photo: Jason Brown
11. Abu Kamara - 6
(Replaced by Terry Devlin on 79 mins. Earned a penalty when his shot was handled by Balmer, but otherwise a very quiet game. Struggled to really spark down the left flank and disappointingly often on the periphery of the match. Photo: Jason Brown
12. Portsmouth forward Paddy Lane (32) Port Vale defender Nathan Smith during the EFL Sky Bet League 1 match between Portsmouth and Port Vale at Fratton Park, Portsmouth, England on 7 October 2023.
Paddy Lane takes on Port Vale's Nathan Smith down Pompey's right. Picture: Jason Brown/ProSportsImages Photo: Jason Brown