Pompey climbed back into the play-off places after securing a deserved League One victory at Shrewsbury – despite playing a quarter of the contest with just 10 men.
They controlled possession, with goals from Marcus Harness and John Marqus securing a commanding lead at the break.
But Nathanael Ogbeta reduced the hosts’ deficit early in the second half and the Shrews were then given an extra boost.
Marquis was shown a controversial red card for a challenge on Harry Chapman, but the Blues saw the game out with relative ease to ensure the points would be heading back to the south coast.
Danny Cowley made four changes from the side that beat Ipswich on home soil in his first game in charge the previous week.
There were returns from injury for Marquis and Callum Johnson, while Michael Jacobs and Ben Close also started.
James Bolton and Andy Cannon dropped to the bench, with the injured Jordy Hiwula missing out completely and Ronan Curtis away on international duty.
Former Pompey striker Curtis Main was in the hosts’ line-up, although manager Steve Cotterill was still missing from the dug-out, as he continues his recovery from a Covid-enforced stay in hospital.
In a slow opening to proceedings it was the Shrews who were first to threaten, with Dan Udoh spinning on the edge of the box and firing in a low show that was saved by Craig MacGillivray.
But the Blues soon settled and began to dominate possession, while asking questions of their opponents’ back three.
Close lifted a pass into the mixer, where Ryan Williams rose to deftly flick the ball inches past the post.
Tom Naylor then tried to glance home a corner from Jacobs, but could not get enough on his header to guide it on target.
And the deadlock was broken on 25 minutes after Johnson had played a neat one-two with Williams down the right.
He then laid the ball off for HARNESS, who neatly bent the ball into the side of the net to make the pressure count.
They almost had a second when the ball pinged dangerously around the Shrewsbury box, but Harry Burgoyne denied Williams from point-blank range.
The Blues were on top, though, and unsurprisingly doubled their advantage on 36 minutes, with the impressive Close involved.
He lifted a pass towards Lee Brown at the far post and the left-back sent the ball across the face of goal, with MARQUIS on hand to find the net from a yard out.
Even when the hosts were able to get into Pompey’s area in stoppage-time, Naylor was back to dispossess Ogbeta.
Half Time: Shrewsbury 0 Pompey 2
The visitors appeared to be cruising, but conceded a soft goal soon after the restart to allow their opponents back into the contest.
Ogbeta collected the ball on the left and was given far too much space to race towards the edge of the box and stroke a shot into the bottom corner.
Pompey tried to hit back and a dangerous Harness delivery was turned behind, while Marquis was tackled before he could get a strike away.
Harness then cut the ball back from the right and there was another spot of pinball before the hosts was able to clear.
Shrewsbury then threatened at the other end, although Main flicked a Chapman cross straight into MacGillivray’s arms.
But Pompey were reduced to 10 men midway through the second half, with Marquis the man to be sent off.
He slid in on Chapman and appeared to win the ball, but also caught the Shrews substitute and referee Benjamin Speedie deemed it dangerous enough to issue a red card.
Cowley made a change shortly afterwards, with Jacobs making way for Cannon to shore up the midfield.
And the lively Close was then replaced by former Shrews defender Charlie Daniels for the closing stages.
Pompey were not being put under too much pressure from their hosts as they attempted to see the contest out.
A display of seven additional minutes might have caused nerves to rise among the visiting ranks, but they held on to celebrate another vital victory.
Shrewsbury (3-4-1-2): Burgoyne; Pennington (Pyke 82), Ebanks-Landell (c), Williams; Sears (Chapman 46), Davis, Vela, Ogbeta; Goss (Whalley 69); Udoh (Edwards 69), Main
Goals: Ogbeta 52
Subs not used: Bevan, Bloxham, Caton
Pompey (4-2-3-1): MacGillivray; Johnson, Whatmough, Raggett, Brown; Naylor (c), Close (Daniels 84); Harness, Williams (Nicolaisen 90+5), Jacobs (Cannon 75); Marquis
Goals: Harness 25, Marquis 36
Sent off: Marquis
Subs not used: Ward, Bolton, Byers, White
Referee: Benjamin Speedie