Pompey’s woeful start to the League One season continued as they fell to a 1-0 defeat at Wycombe Wanderers.
Adebayo Akinfenwa grabbed the only goal from the penalty spot in the 82nd minute, with both sides ending the game with 10 men.
Ellis Harrison was dismissed for a second yellow card for his part in a melee following Nnamdi Oforborh being sent off for a straight red card.
It means the Blues drop to 20th in the table and boss Kenny Jackett comes under increased pressure, with sections of away supporters singing ‘We Want Jackett Out’ after watching their side go a goal behind.
Pompey made four changes from Tuesday’s 2-2 draw with Burton.
Oli Hawkins started at centre-back alongside Christian Burgess, while James Bolton was handed his first League One start for the Blues.
Andy Cannon and Ellis Harrison also came into the starting XI.
The Blues had an effort on goal in just the first minute but Tom Naylor skewed his left-footed half-volley well off target.
On four minutes, Ronan Curtis cut in from the left but dragged his shot wide.
It proved a disjointed first half throughout and Ellis Harrison had a decent opportunity to break the deadlock in the 13th minute.
Ben Close slipped in the forward but he couldn't steer his right-foot effort on target, while John Marquis’ low shot was blocked by Harrison on 28 minutes.
The opening 45 minutes was typified by Wycombe’s first and only shot in added-time.
A long throw-in could only be cleared as far as Darius Charles and he not only sent his effort over the bar but out of Adams Park.
The game burst into life in the 54th minute when both sides were reduced to 10 men.
Nnamdi Ofoborh’s rash challenge on Naylor saw referee Seb Stockbridge immediately draw the red card from his back pocket.
A melee following the challenge ensued in front of the dugout.
Adebayo Akinfenwa and Christian Burgess were both booked, while Harrison collected his second yellow card and given his marching orders.
That spiced up what was previously a mundane affair. On 62 minutes, Curtis’ curling free-kick was tipped out by Allsop, with Burgess’ effort then being cleared for a corner.
The Chairboys’ best opportunity fell to Scott Kashkett in the 70th minute. His effort looked to be heading for the far corner, only for Craig MacGillivray to make a fine stop to his left.
The Blues broke on the counter-attack, with Close having a 25-yarder deflected narrowly wide.
The deadlock was finely broken in the 83rd minute, with Pompey masters of their own downfall.
Naylor was judged to have handled inside the area, with the referee immediately pointing to the spot.
Akinfenwa stepped up and, despite MacGillivray guessing correctly, couldn’t get to the striker’s effort.
That prompted chants of ‘We Want Jackett Out’ from some of the Fratton faithful, who're clearly frustrated with Pompey’s form.
Brett Pitman went close to grabbing an equaliser on 87 minutes but headed Brandon Haunstrup’s cross against the bar.
Seven minutes of added-time were indicated but the Blues failed to conjure a real opportunity.I
It meant Pompey were condemned to a third league defeat of the campaign and have picked up just six points from a possible 21.
Boos rung out from the away section at full-time, with the Blues sitting just two points above the relegation zone, while Jackett received a similar reception when applauding the travelling supporters going down the dugout.