Pompey supporters turned on their manager for the first time during a match as the Blues slumped to a dismal 1-0 defeat at Wycombe.
Following Adebayo Akinfenwa’s decisive penalty on 83 minutes, members of the 2,125 away following chanted ‘We want Jackett out’.
There was a reprise at the final whistle at Adams Park, although noticeably not as loud, as fans drifted away fuming at the display they had witnessed.
The loss means Pompey have won just one of their opening seven league fixtures, finding themselves languishing 20th in League One.
Ominously, Tuesday brings a south-coast derby with Southampton in the Carabao Cup.
And the under-fire Jackett conceded their Chairboys performance was not of the required standard.
He said: ‘I did hear what they were saying and obviously understand their frustration because we couldn't get going.
‘Ultimately, the frustration comes on the manager, that’s the nature of it.
‘We look forward to Tuesday and trying to make sure we put it right. Of the changes, Oli and James should be able to build on that and for other players there are better performances in them.
‘That (crowd) reaction is there as a manager and not something you shrug off, dismiss or enjoy.
‘We have won one game out of the first seven in the league and, for myself, you look onto Tuesday and Saturday to try to get it right then.
‘One win out of seven isn’t what we want and on Saturday we didn’t get going, didn’t get going on the ball, didn’t get going forward unfortunately and that is a frustration and a fact.
‘We can look at the referee’s decisions and maybe this, maybe that, but we can do better than that.
‘We have Southampton next and won’t sweep Saturday under the carpet, we have to learn from it and try to climb and grow. We can do better than we did.’
Another disappointing aspect of their Adams Park loss was the poor quality of set-piece plays.
Andy Cannon, Ronan Curtis and Brandon Haunstrup all stepped up for duty – yet the calibre was noticeably lacking.
Jackett added: ‘Ultimately, Wycombe got a far-post ball from a corner, it’s handball and Akinfenwa has put the penalty away.
‘It was a set-piece – and for us that has been the difference.
‘Whereas we struggled for delivery. At the moment we are struggling for consistent delivery, we certainly have enough big players and players who can score from there if the right ball comes in.’