Colby Bishop continued his prolific form with a brace as Pompey beat Bristol Rovers to record their second away victory of the week.
He gave the visitors an early lead with a fine low finish before wrapping up the points from the spot after the break.
And insult was added to injury for the home side, with Jarell Quansah sent off for violent conduct late on.
John Mousinho made one enforced change from the side that secured victory against Accrington earlier in the week.
Joe Pigott started a three-match ban following his sending off at the Crown Ground, so Ryan Tunnicliffe returned to the starting line-up.
There was also a welcome return to the bench for skipper Clark Robertson, who is fully fit after almost three months on the sidelines.
The hosts were first to threaten and an unmarked Lewis Gibson should have done better than nod Antony Evans’ free-kick straight into the arms of Matt Macey.
Rovers had lined-up in a 4-4-2 formation, despite their manager Joey Barton’s criticism of the formation at Fratton Park earlier in the campaign.
But his side were still looking dangerous and a fierce long-range effort from Aaron Collins was turned around the post by Macey.
It was Pompey who broke the deadlock on 18 minutes, however, when Sean Raggett and Tunnicliffe combined to play through BISHOP.
The striker hit a low angled shot that bounced off one post and then the other before finally crossing the line.
Rovers were furious that the goal was allowed to stand, feeling that Bishop was offside when the ball was played.
Coach Andy Mangan earned a yellow card for his furious protests to the fourth official, as did substitute Glenn Whelan.
The Blues looked to build on their lead and Reeco Hackett’s effort from the left side of the box was smothered by James Belshaw.
They were looking bright in possession and generally dominating the contest, but unable to turn that into more clear-cut openings.
And it might have been level at the break after Collins found John Marquis in the box, but the former Pompey striker blazed over.
Half Time: Bristol Rovers 0 Pompey 1
That miss proved to be Marquis’ final contribution to the game, as he was taken off at the break as part of a double change by the hosts.
Pompey were quickly out of the blocks when the action restarted and Evans did well to turn the ball behind when Bishop tried to pick out Hackett at the back post.
Evans was then involved at the other end, playing a free-kick down the line for Collins, whose teasing cross just evaded the head of Josh Coburn.
Rovers were starting to apply some pressure in the hunt for a leveller and, under close scrutiny from Joe Rafferty, Grant Ward could only nod wide from another Collins delivery.
Mousinho freshened up his forward line with a substitution just before the hour mark, as Hackett made way for Owen Dale.
And with Thompson then seeming to pick up a slight knock soon after, there was also an introduction for Michael Jacobs.
Some good work from Dale on the left led to Pompey doubling their advantage on 69 minutes, with the winger doing well to hold off the Rovers defence and release Connor Ogilvie.
He drove forward and sent in a cross that was fumbled by Belshaw, with Paddy Lane unable to capitalise as he was clearly being tugged back by Calum Macdonald.
Referee James Bell pointed straight to the spot and BISHOP calmly sent Belshaw the wrong way to make it 22 goals for the season.
If there was a sense that the points were secure, minds were soon refocused when Macey was forced to make a fine save to keep out a Luca Hoole header at point-blank range.
And the keeper had to be at his best again moments later, this time diving full length to turn Scott Sinclair’s free-kick around the post.
The home side continued to apply pressure as the seconds ticked down, but were unable to find the goal that would have ensured a tense finale.
And the Blues were even able to give some time on the pitch to Robertson in the closing stages to cap another productive afternoon.
Rovers, meanwhile, ended with 10 men, as Quansah hacked down Morrell and then appeared to headbutt the Wales international.
Bristol Rovers (4-4-2): Belshaw; Hoole, Quansah, Gibson (c), Gordon (Macdonald 46); Evans (Loft 73), Bogarde, Ward (Finley 73), Collins; Marquis (Sinclair 46), Coburn
Sent off: Quansah
Booked: Whelan, Ward, Macdonald
Subs not used: Balcombe, Connolly, Whelan
Pompey (4-3-3): Macey; Rafferty, Raggett (c), Towler, Ogilvie; Tunnicliffe, Thompson (Jacobs 66), Morrell; Lane (Robertson 87), Bishop, Hackett (Dale 59)
Goals: Bishop 18, 69 (pen)
Booked: Tunnicliffe, Morrell
Subs not used: Oluwayemi, Bernard, Lowery, Scarlett
Referee: James Bell
Attendance: 9,448 (1,275 Pompey fans)