The Blues were indebted to the returning Callum Lang for a first win in 11 matches in all competitions this season, with the attacker creating one and then grabbing the winner from the penalty spot.
John Mousinho’s men found themselves behind after just nine minutes when Kader Dembele lobbed into an empty net following Nicolas Schmid’s poor headed clearance.
However, brilliant work from Lang provided the leveller for Freddie Potts on 18 minutes and the the ex-Wigan man won himself a second-half penalty – and converted it.
The Blues held out for a vital victory – and here are our Pompey player ratings...
9. Callum Lang - 9 - Man of the Match
(Replaced by Elias Sorensen on 80 mins) Been hugely, hugely missed. Returned to the side after three matches out through a groin injury and after 18 minutes had himself an assist after brilliantly teeing up Potts for the leveller. Then won a second-half penalty after chasing down Fox, scoring from the spot kick. What an all-action display. Photo: Gary Oakley
10. Christian Saydee - 6
(Replaced by Paddy Lane on 62 mins) Couldn’t quite find a foothold in the game, finding little opportunity to drive with the ball and not asked to retain possession in advanced positions. Photo: Jason Brown
11. Josh Murphy - 7
(Replaced by Terry Devlin on 80 mins) One of his quieter games and not hugely effective as an attack force. However, is always a good outlet on the left flank and capable of making something happen. Photo: Jason Brown
12. Mark O'Mahony - 6
(Replaced by Kusini Yengi on 71 mins Extremely quiet afternoon, barely given a sniff and marshalled superbly by the QPR backline. Work hard but just couldn’t make an impact. Photo: Jason Brown