A goal in each half saw Pompey pick up back-to-back league wins following victory against Blackpool.
Gareth Evans and Eoin Doyle’s stoppage-time goal saw the Blues pick up a 2-0 success.
That lifts Paul Cook’s side up to fifth in League Two as impetus is injected into their season.
A free-flowing first half became an increasingly nervy second but Pompey held on for the success.
The first 45 minutes saw Pompey in dominant form as the Fratton Park crowd got behind their side.
Gary Roberts cracked the bar with a great chance after just five minutes from Eoin Doyle’s cross.
Further half-chances followed before Evans put his side in front after 27 minutes.
It was a goal which made for pleasant viewing for Cook as left-back Enda Stevens crossed for right-back Evans to convert in the box as he gambled with his forward run.
At the other end, Kyle Vassell’s angled shot was turned around the post by David Forde, and referee Darren Deadman ignored penalty appeals as Vassell tussled with Christian Burgess in the box in Blackpool’s best moments of the half.
Eoin Doyle had strayed offside as Roberts headed over the top five minutes after the restart.
The evening needed that second goal to stop the nerves jangling.
Instead Pompey had Stevens to thank for making a super block to deny Brad Potts a certain goal with 14 minutes left.
And then Tom Aldred headed past the post as Fratton Park held it breath,
Stiker Doyle then got reward for his endeavour right at the death as he slid in substitute Carl Baker’s pass as Fratton Park cheered the final whistle.