It was the second time in a week that Pompey played out a dramatic 2-2 League One draw.
There were celebrations when Sean Raggett slotted home a stoppage-time equaliser against Plymouth at Fratton Park on Tuesday night.
But it was a different story at The Valley, where the visitors twice let slip a two-goal lead to increase their winless run to six games.
Ronan Curtis’ fine early strike was cancelled out by Sean Clare and although Marcus Harness restored the advantage, Josh Davison grabbed a late leveller for the Addicks.
And Danny Cowley was frustrated that his troops were not able to make the most of their large spells of dominance.
The Blues boss said: “I thought that we probably created enough chances to win three football matches.
“When you come away from home and dominate the way we did in the first half, we’re obviously disappointed not to win the game.
“We were excellent in our play before the break and the game-plan was delivered perfectly, so credit to our lads for that.
“At half-time we should have been further ahead and our opponents were forced into a change, but that’s the second time in a row we’ve conceded straight after the restart.
"I thought that we probably created enough chances to win three football matches."
“We fought our way back, though, and scored a really good goal and had more chances to get a third and wrap things up.
“So we’re really disappointed that we haven’t won the game, particularly with how well we’ve played.
“But if you concede two goals then football generally suggests that you won’t – it’s much easier to get a 1-0 or 2-1 victory than it is a 3-2.
“We gave a needless free-kick away for the first and then didn’t do our job to deal with it, while they got an overload for the second.
“Our supporters were incredible – just imagine if we could create a winning team. The way they backed us was magnificent and really inspired me.”
It was a mixed afternoon for John Marquis, who missed a great chance in the first half before providing the assist for Harness.
Cowley said: “John did great for Marcus’ goal and defended from the front brilliantly. Your heart is with him because that work-rate is so selfless.
“He’s missed some chances and that’s the life of a number nine. He was born to score, though, and we have belief that he can do that.
“John came into the dressing room afterwards and apologised, but you can’t do that when you’ve worked as hard as he did for the team. He gave us so much.”