The Blues missed a string of chances as they produced their best away performance of the season against the second-placed Sheffield United.
Colby Bishop, Colby Bishop and Connor Ogilvie failed to take glorious opportunities, before substitute Jesurun Rak-Sakyi won it in the 73rd minute.
Earlier, Ogilvie converted the impressive Josh Murphy’s cross to level three minutes after Gustavo Hamer had opened the scoring. And here are our Pompey player ratings...
5. Rob Atkinson - 8
Rock solid and getting more and more up to speed as he proves a fantastic signing. Defends with power and heart and such a key player in survival. Photo: Jason Brown
6. Connor Ogilvie - 8
Produced a striker’s instinctive finish to level in the first-half, then a defender’s shot to miss an open goal on stroke of half-time. Nonetheless, an excellent showing once more from the left-back who continues to grow in the Championship. Photo: Jason Brown
7. Andre Dozzell - 8
(Replaced by Kaine Gordon on 81 mins) Another strong performance from the Burnley man of the match. Seemed to be absolutely everywhere, closing, pressing and putting his foot in. Rapidly becoming a central figure. Photo: Jason Brown
8. Freddie Potts - 7
(Replaced by Marlon Pack on 90 mins) Back to his normal output following a couple of below-par displays. Used the ball sensibly, retained possession and chased and closed non-stop. Photo: Jason Brown