Brett Pitman’s blushes were spared as his only goal delivered Pompey a much-needed 1-0 victory over Bolton in League One.
The forward crashed a second-half penalty against the post but made up for his miss by heading home seven minutes later at Fratton Park.
That delivered the Blues just a second win of the league campaign against the struggling Trotters and eased some pressure off under-fire boss Kenny Jackett.
Pompey made one change from the south-coast derby defeat to Southampton on Tuesday, with Sean Raggett replacing the injured Oli Hawkins in central defence.
Marcus Harness also returned from the substitutes’ bench having recovered from a thigh strain, while Ellis Harrison was named in the 18-man squad following his one-match suspension.
The Blues conjured their first chance within two minutes when Brandon Haunstrup’s free-kick was headed back across goal by John Marquis, but Brett Pitman couldn't get enough purchase on his effort.
On eight minutes, home keeper Craig MacGillivray was called into action. Raggett’s poor clearance allowed Will Buckley an opportunity but MacGillivray got down well to save the effort to his left.
There was a hear-in-the-mouth moment for Pompey in the 17th minute. Thibaud Verlinden cracked a left-footed shot which was heading for the far corner, only for Christian Burgess to make a crucial sliding block.
Ronan Curtis should have done better when he was gifted a chance on 31 minutes. Marquis’ pass was dummied by Pitman for the Irishman, but he took too many touches and was dispossessed inside the box.
It was MacGillivray the busier of the two keepers and 10 minutes before the break he couldn't handle Adam Chicksen’s effort before the hosts cleared the loose ball.
The Trotters had a golden chance to break the deadlock in the 43rd minute when they hit Pompey on the counter-attack but Buckley couldn’t steer his first-time effort on target when left in all sorts of space at the back post.
Jackett’s side had the chance to go into half-time with the advantage in stoppage-time. After Ryan Williams was brought down 25 yards from goal, Pitman’s free-kick forced an unorthodox save out of visiting stopper Remi Matthews.
The Fratton Park boss changed things at half-time, with Harness replacing Williams.
It was the visitors who had the first chance of the second half, with Daryl Murphy's angled effort being well held by MacGillivray.
On 59 minutes, Pompey were given a gilt-edged opportunity to open the scoring.
Curtis shifted the ball for Marquis inside the box and he was fouled by Hobbs, with the referee pointing to the penalty spot.
Pitman stepped up and sent Matthews the wrong way – but crashed his spot-kick against the post.
Yet the striker would atone for his miss seven minutes later with a superb opening goal.
A lovely move from the Blues culminated in James Bolton's cross picking out Pitman at the back stick and he hung in the air before guiding his header into the far corner.
And Pompey went agonisingly close to adding a second with six minutes remaining. Ben Close created himself space on the edge of the box but his shot just flashed wide of the right-hand post.
In added-time, there was a worry for Pompey by Crawford’s long-range free-kick had MacGillivray diving at full length but the effort went just wide.
Then the Blues went up the other end with Harness teeing-up Close on the edge of the box but the midfielder blazed his shot over the bar.
Jackett’s men held on for just their second league win of the season and moved one place up in the table to 19th.
Pompey: MacGillivray, Bolton, Raggett, Burgess, Haunstrup, Naylor, Close, Williams (Harness 46), Pitman, Curtis (Evans 62), Marquis.
Subs not used: Bass, Walkes, McCrorie, Cannon, Harrison.
Bolton: Matthews, Emmanuel (L Murphy 67), Hobbs, Zouma, Chicksen, Bridcutt, Lowe, Crawford, Verlinden, Buckley, D Murphy.
Subs not used: Alexander, Weir, Politic, Boon, Senior, Graham.