Joe Pigott came off the bench to head home the only goal of the game and secure Pompey a victory against Accrington.
In a contest that drifted along for long periods, there was little to get another large Fratton crowd off the seats.
But Pigott capitalised on a fine delivery from Michael Jacobs to ensure the Blues ended their run of draws.
John Mousinho made two changes from the side that were held to a draw at Oxford earlier in the week.
Harry Jewitt-White was handed a first league start, while January signing Ryley Towler returned to the defence.
Sean Raggett dropped to the bench, while Ryan Tunnicliffe was absent from the matchday squad completely.
It was a lovely sunny afternoon on the south coast and the first half very much felt like end-of-season fare as it drifted along at times.
Accrington showed some early purpose and won a couple of corners, but there was nothing to trouble Matt Macey between the sticks.
There were a trio of long-range attempts from Ethan Hamilton and each one flew comfortably into the keeper’s arms.
Connor Ogilvie swung in a dangerous delivery at the other end, with Tom Lowery firing wide from the tightest of angles.
Joe Rafferty also exchanged passes with Towler in the box and saw his low shot deflected past the post.
And the lively Jacobs swung in a teasing corner just before the break that was punched away by Lukas Jensen.
The keeper did not have much else to do, however, as the Blues showed some nice touches, but were unable to turn that into clear-cut opportunities.
Half Time: Pompey 0 Accrington 0
The contest failed to explode into life once the action restarted, with Pompey seeing plenty of the ball and their opponents remaining organised at the back.
There was one spell of neat passing play and when the ball was sent in, Michael Nottingham managed to prevent Colby Bishop from getting on the end of it.
Paddy Lane then collected Rafferty’s ball down the right and cut inside, with his first shot blocked and the second dragged wide.
The Northern Ireland international soon had another attempt from the edge of the box, but this one flew narrowly over.
Mousinho made a switch just past the hour mark, with the impressive Jewitt-White given warm applause as he was replaced by Pigott.
And the hosts went close again soon after, as Marlon Pack’s header from Rafferty’s cross looped onto the roof of the net.
The breakthrough finally arrived on 75 minutes, with Jacobs providing a fine cross for PIGOTT to convert with a close-range header that went in off the underside of the bar.
Accrington had not offered much since the restart, but Harvey Rodgers wasted a free header before Nathan Butler-Oyedeji charged down Macey’s clearance and the ball ricocheted to safety.
Pompey then had a chance to wrap the points up when they broke quickly up the pitch from a Stanley corner.
It was not a perfect pass from Ogilvie, but Bishop brought it under control well before drilling just wide.
The hosts then received a huge let-off when substitute Aaron Pressley somehow managed to fire the ball over the bar from just a few yards out.
Stanley players and staff dropped to their knees knowing it was a great chance to level and that was their final chance to depart with a point.
Pompey (4-3-3): Macey; Rafferty, Bernard, Towler, Ogilvie; Lowery, Pack (c), Jewitt-White (Pigott 64); Lane (Raggett 90+3), Bishop, Jacobs (Dale 86)
Goals: Pigott 75
Subs not used: Oluwayemi, Robertson, Thompson, Scarlett
Accrington (4-2-3-1): Jensen; Clark, Rodgers, Nottingham, Sangare (Tharme 72); Leigh (Quirk 42), Hamilton; Longelo, Nolan (Butler-Oyedeji 76), McConville (c); Lowe (Pressley 76)
Booked: Clark, McConville
Subs not used: Savin, Martin, Whalley
Referee: Darren Drysdale
Attendance: 17,594 (126 away fans)