Pompey are out of the FA Cup after an abject performance at Fratton Park against Wycombe Wanderers who deserved their win on the day.
The first half showing from Paul Cook's men was the worst of the season for a home match as a weakened Pompey side failed to register a single meaningful attempt at the Chairboys' goal.
The visitors had plenty of attempts of their own as Matt Bloomfield struck the post and David Forde denied ex-Pompey starlet Paris Cowan-Hall with his trailing leg after the latter was put through on goal.
He did find the back of the net soon after, however, as an unsure Forde punched the ball into the back of Christian Burgess and Cowan-Hall was there to head in the opening goal from close range.
Adebayo Akinfenwa should have doubled the lead right before the break but could only head the ball wide of the target at the far post as no Pompey player picked up the biggest man on the pitch.
The second half display couldn't be as inept as the first and so it proved to be as Gareth Evans turned in Enda Stevens' cross after just two minutes.
Paul Cook made a double substitution after the hour with Carl Baker and Kyle Bennett coming on for the ineffective Milan Lalkovic and the returning Adam Buxton. They both made an impact, with Baker forcing an excellent save from Jamal Blackman in the Wycombe goal.
Forde made an equally impressive stop from Akinfenwa's long range effort as well as a couple of other saves after the defenders in front of him had deserted him.
But he was to blame for Wycombe's eventual winner as he was too far off his line and got caught out by a looping header from Akinfenwa as the Pompey defence yet again failed to deal with a simple long ball.
There was one massive chance for Pompey to equalise in stoppage time as a corner was sent back across the Wycombe goal but Stevens' diving header went wide of the target.
The final whistle was greeted by boos from the majority of the 8,130 fans who were in attendance to witness such a woeful performance as Portsmouth were knocked out of the FA Cup at the first hurdle for the sixth time in seven seasons.
A number of Pompey fans were calling for the manager's head after the match and it's not difficult to see why as he failed to motivate his team and arguably should have selected a stronger side, especially as Gareth Ainsworth picked what seemed to be his strongest eleven.
However, whilst Cook can rightfully be criticised for his lack of tactical flexibility and questionable motivational skills, his players really let him down.
Forde may have made a few decent saves but his indecisiveness meant he was at fault for both Wycombe goals. Having said that, the back four really should have dealt with the simple long balls and set-pieces better than they actually did, but this has been a problem ever since Pompey were relegated to League Two.
The back four didn't cover themselves in glory but they didn't receive much protection from the two defensive midfielders in front of them. Ben Close looked out of his depth whilst Danny Rose constantly gave the ball away. Michael Doyle was certainly missed, that's for sure.
It wasn't just defensively where Pompey failed to produce as the attack were as blunt as a Jeremy Paxman interrogation in the first half. Lalkovic, for all of his skill, didn't actually carry the ball forward when he had it whilst Gary Roberts struggled to have an influence on the game once again with an increasing number of fans calling for him to be dropped.
Noel Hunt offered little up front too and should have been withdrawn earlier. It was all very disjointed apart from a brief spell in the second half when Baker and Bennett looked to have rejuvenated a flat Pompey performance.
This defeat marks Pompey's fourth home loss in a row (if you count the penalty shootout defeat to Reading in the EFL Trophy) and that is certainly a cause for concern.
But calls for Cook to be sacked are premature as his team are still well positioned in the league to make a challenge for automatic promotion. Nobody will care about this result if Pompey are a League One team next season, after all.
However, yesterday's sorry showing has seen more fans lose faith in the manager and only a win against Mansfield on Saturday will help change their opinions on a man who is becoming more unpopular as autumn turns to winter.
Pompey Player Ratings
David Forde: 5 - Saves can't mask the two crucial errors he made for the goals.
Adam Buxton: 5 - Not the man to solve Pompey's right back problem based on this performance.
Christian Burgess: 5 - Lacked communication with Forde.
Matt Clarke: 5 - Marking was slack.
Enda Stevens: 6 - Played a part in Pompey's goal and almost equalised at the death.
Ben Close: 4 - Didn't look good enough.
Danny Rose: 4 - Lost the ball too often.
Gareth Evans: 7 - Did a good job wherever he was asked to play.
Gary Roberts: 5 - Missing for large parts of the match.
Milan Lalkovic: 5 - Ineffective.
Noel Hunt: 4 - Barely made an impact.
Carl Baker (Buxton 64): 6 - Added some attacking threat.
Kyle Bennett (Lalkovic 64): 6 - Did more in ten minutes than Lalkovic did all match.
Conor Chaplin (Hunt 75): N/A - Didn't have a chance.