"Let us hope we are there in March in a challenging position, and then we shall see if we fall away again," said a relieved Curbishley.
"I was disappointed and the only saving grace for us was that it was only one at half-time. We wanted them to work harder in the second half, because we felt that they had been out-worked and that showed after the break."
Portsmouth took a deserved lead on 14 minutes, defender Andy O'Brien picking out the run of striker Dario Silva with a fine raking pass. The Uruguayan international set himself up after allowing the ball to bounce twice, before firing in his first goal for the South Coast club from an acute angle.
Darren Ambrose was buzzing with a purpose, the young midfielder coming close twice in as many minutes, firstly with a mazy run after being set up by Darren Bent. Jamie Ashdown, though, was equal to the low shot, and would be called on again moments later as Ambrose again tested the Portsmouth goalkeeper.
For the Portsmouth manager Alain Perrin, whose team looked set for their first home win of the season, the pressure was telling as he agitatedly paced his technical area.
Charlton were responding to the efforts of their hosts, and Perrin would not have been pleased. Nor would his chairman Milan Mandaric, sitting over in his shoulder in the stand behind him.
After the break the home crowd would have been expecting slightly more forward-thinking football, and more purpose, in a bid to break down any remaining resilience. But Portsmouth, though still relatively untroubled by the visitors, were too cautious.
That approach saw them stung on 60 minutes when Ambrose fired home a neat pass from Danny Murphy, the result of some intricate play outside the penalty area.
Portsmouth's response was anything but positive, and as they retreated following the equaliser, they were again caught out. Zvonomir Vukic, one of the home side's better performers in the first half, lost the ball through careless play.
This allowed Murphy to thread another deft pass, this time to Dennis Rommedahl, the Danish midfielder turning well before emphatically firing the second past a helpless Ashdown.
Murphy said: "If we keep playing good football, like we showed in the second half, we will win more than we lose and that is our objective, maintain a level of consistency."
Goals: Silva (14) 1-0; Ambrose (61) 1-1; Rommedahl (77) 1-2.
Portsmouth (4-3-3): Ashdown; Stefanovic, O'Brien, Priske, Vignal; Viafara, O'Neil, Taylor (R Hughes, 87); Silva, Vukic (Mbesuma, 88), Robert (Todorov, 87). Substitutes not used: Westerveld (gk), Griffin.
Charlton Athletic (4-5-1): Andersen; Young, Hreidarsson, Perry, Spector; Kishishev, Murphy (El Karkouri, 90), Ambrose, Rommedahl (Johansson, 83), Smertin; Bent. Substitutes not used: Kiely (gk), B Hughes, Bothroyd.
Referee: H Webb (S Yorkshire).
Booked: Portsmouth Robert, Vignal; Charlton Athletic Kishishev, Hreidarsson, Ambrose.
Man of the match: Murphy.