Pompey recorded a much-needed away win as they dispatched Walsall 3-2 at the Banks’s Stadium.
With pressure on to remain within touching distance of League One’s top two, they did just that with a hard-fought victory at the Saddlers.
And with Barnsley and Sunderland drawing 0-0 at Oakwell, they closed to gap on the automatic promotion places to six points, with nine games remaining.
Brett Pitman opened the scoring for the Blues from the penalty spot on 13 minutes.
Omar Bogle made it 2-0 on 25 minutes after a long clearance from keeper Craig MacGillivray.
Viv Solomon-Otabor added a third midway through the second half, before a Jon Guthrie double near the end put some unnecessary pressure on the visitors.
Pompey took the lead on 13 minutes following a needless challenge on Nathan Thompson inside the Walsall penalty area.
Referee Trevor Kettle immediately pointed to the spot following Morgan Ferrier’s shove on the Blues right-back.
And in his first league start since the defeat to Luton on February 29, Pitman found the back of the net from 12 yards, sending keeper Liam Roberts the wrong way.
The goal came with the visitors down to 10 men at the time.
Matt Clarke was receiving treatment for a bloodied nose and head wound on the sidelines - but his continued absence had little effect as Pompey got the early goal they craved.
The Blues had the chance to extend their lead on 22 minutes when Thompson’s cross picked out Lowe.
The winger, however, fluffed his effort, before Solomon-Otabor - in the side for the injured Ronan Curtis - was closed down to prevent him firing goalwards from close range.
A mistake by Clarke handed Walsall the chance to draw level three minutes later.
However, Ferrier’s first touch took him wide and the angle was too tight for him to truly test MacGilivray, who gathered at the second attempt.
The keeper’s next move was to kick the ball forward - and it was a clearance that set up the Blues for their second goal.
Bogle got in on the end of it and lifted the ball over the onrushing Roberts to net his third goal - via the post - since joining on loan from Cardiff in the January transfer window.
Jackett’s side looked comfortable at this stage, with the Saddlers lively in flashes.
Yet Pompey will have been disappointed not to enter the break with a three-goal advantage, after Lowe wasted a golden opportunity when oput through by Pitman.
Walsall threatened straight from the restart, with Josh Gordon attempting to catch MacGillivray with a quick header.
And the Saddlers maintained that early momentum in the second half when Brown had to be extra alert to clear a dangerous ball from the left under pressure at the back post.
The signs were there that the Blues had weathered the storm, with the hosts struggling to test MacGillivray further.
Meanwhile, Bogle’s header from Lee Brown’s cross just after the hour mark suggested there were further goals in this for Pompey.
On 68 minutes Lowe was put through again, after some industrious work from Pitman in the middle of the park.
On this occasion, though, he made the most of the opportunity.
He picked out Solomon-Otabor with an inch-perfect pass, and the on-loan Birmingham man made no mistake by firing home his first goal for the club.
At this stage, the hosts looked dead and buried.
But the home supporters showed signs of life when Jon Guthrie’s header from a corner lifted spirits on 75 minutes.
They were furthered buoyed when Walsall appealed for a penalty two minutes later after the ball appeared to strike Clarke’s arm.
But the ref was having none of it and quickly waved play on.
The visitors had the chance to finally put the game to bed on 82 minutes when they broke free in numbers.
However, the combination of Lowe, Otabor and Naylor failed to unlock a struggling Saddlers defence when the opportunity was there.
Guthrie caused a degree of panic in the Blues ranks when he scored a second goal deep into stoppage-time.
However, it was too little too late as Pompey recorded their first away win in the league since the turn of the year.