The Blues were badly running out of ideas, with Abu Kamara the chief culprit towards the end, as the match threatened to peter out for a frustrating goalless draw.
But Kamara was brought down and unpopular referee Craig Hicks pointed to the spot for Bishop to net – and here are our Pompey player ratings...
9. Paddy Lane - 6
(Replaced by Josh Martin on 82 mins) Played in fits and starts, but largely a quiet afternoon. Produced one decent shot which brought a save out of Ripley early in the first half, yet didn’t have enough of the ball to consistently threaten. Photo: Jason Brown
10. Abu Kamara - 5
Just not at it. Caught in possession from goal-scoring positions in the first half because he wanted it on his left foot and later one awful shot was heading for a throw-in before deflected for a corner. Also poor late miss after Devlin cross. Then he won the late penalty converted by Colby Bishop. It's a funny game! Photo: Jason Brown
11. Colby Bishop - 7
(Replaced by Ryley Towler on 90 mins) Drew a scrambling save from the goalkeeper with a header on the stroke of half-time. Frustratingly elected to hold up the ball when clean through on a couple of occasions, seeking to bring others into play, rather than shooting. Then he struck an 88th-minute penalty. Photo: Bryn Lennon
12. Portsmouth midfielder Myles Peart-Harris (44) during the EFL Sky Bet League 1 match between Port Vale and Portsmouth at Vale Park, Burslem, England on 27 January 2024.
Myles Peart-Harris was handed an instant Pompey start against Port Vale following his arrival from Brentford. Picture: Jason Brown/ProSportsImages Photo: Jason Brown