Pompey fell to a hapless 1-0 defeat at Bury as their failure to make the League One play-offs was confirmed.
George Miller was gifted a tap-in by Blues keeper Luke McGee midway through the second half on a lacklustre afternoon for Kenny Jackett’s side at Gigg Lane.
Conor Chaplin and Christian Burgess had two late chances to amend the error by the Pompey No1, but the already-relegated Shakers deserved their three points.
Bury had a few half-chances early on, with Harry Bunn and Jay O’Shea both missing the target with speculative efforts.
Oli Hawkins missed a gilt-edged opportunity in the 24th minute - although the assistant referee spared his blushes as the striker was ruled offside.
Jamal Lowe’s floating cross picked out the striker six yards from goal at the back post, but Hawkins’ diving header failed to make Shakers keeper Joe Murphy work.
Lowe’s angled shot on the stroke of half-time missed the target, but, in truth, it was a humdrum of a first half.
The Blues started the better of the two sides after the break and Hawkins headed over Lowe’s left-footed cross on 51 minutes.
Burgess also failed to steer an aerial effort on target from Connor Ronan’s corner eight minutes later.
Jackett’s side were given a warning when Brett Pitman cleared Miller’s shot off the line following a goalmouth scramble in the 67th minute.
But the Bury forward opened the scoring seconds later with perhaps the easiest goal of his career.
McGee tried to Cruyff turn Miller, but he nicked the ball off the keeper and it rolled into the empty net.
Substitute Matty Kennedy was presented with a golden chance to equalise nine minutes from time but his right-footed shot from inside the box lacked purchase and failed to trouble home keeper Joe Murphy.
The Blues twice came close to grabbing a point at the death when Chaplin was denied by a good save from Murphy, before Burgess’ header from the subsequent corner was cleared off the line.
But Pompey were second best for the majority on their final away game of the season.
They dropped to ninth in the table, with a top-six finish now mathematically out of question.