Pompey were punished for making crucial defensive errors as they were condemned to a 2-0 defeat at Shrewsbury Town.
Shaun Whalley and Stefan Payne scored for Paul Hurst’s high-flying side, taking advantage of mistakes from Luke McGee and Matt Clarke at the New Meadow.
And things could have been even worse for Kenny Jackett’s troops but for McGee keeping out Whalley’s penalty when the game was at a stalemate.
The first half wasn’t one for the purists and there were few clear goalscoring opportunities.
On eight minutes, Shrewsbury appealed for a penalty when Carlton Morris went down under a challenge from Matt Clarke but referee Darren Handley instead pointed for a goal kick.
Jon Nolan had the first sight on goal in the 18th minute when he blazed wide.
A minute later, Matty Kennedy engineered Pompey’s first chance when the Scot’s 30-yard effort was pushed away by Dean Henderson.
The visitors started the second half with more purpose but needlessly conceded a penalty on 53 minutes when they paid the price for indecision.
Neither Christian Burgess nor McGee took charge of a long ball over the top. As a result, Morris alertly nipped in and was brought down after rounding the Pompey goalkeeper.
However, the former Tottenham Hotspur man made amends for his error by keeping out Shaun Whalley’s poorly-struck spot kick a minute later.
At the other end, Pitman’s 20-yard free-kick from Henderson in the 56th minute.
The breakthrough came on 59 minutes through a mistake from McGee.
Jon Nolan’s shot was deflected off Clarke and the Pompey’s goalkeeper tried to avoid the ball running for a corner.
However, McGee spilt the ball and Whalley took advantage and smartly finished from a tight angle.
And Shrewsbury were gifted their second 10 minutes from time.
Clarke got caught in possession by Abu Ogogo and he fed in substitute Payne, who slotted his effort under the Blues goalkeeper to wrap up the three points.
The defeat ended Jackett’s side’s run of four successive victories and they dropped to eighth in League One.