The two clubs had been without a point prior to today, and Charlton looked like heading back to London still on zero as Chris O'Grady's double put the home side clear.
But substitute Jordan Cousins got one back before Simon Church equalised as Charlton showed the sort of spirit they will need to defy some of the predictions made about their chances this season.
This was still a far cry from their 6-0 drubbing of the Tykes just a matter of months ago, but it at least gave Powell something to smile about.
"We fought our way back. In the first half Barnsley were excellent and they deserved to be in front," said the former England defender.
"At half-time we could have been two or three down. But after a few choice words at half-time we went out and got our season up and running."
O'Grady had been too hot to handle for Charlton for the first hour, bundling in a loose ball and then heading home a Jacob Mellis cross.
But Charlton found a way to cancel out the rangy frontman and hit back with goals of their own.
"When we went two down you are looking for strength and character and looking to see if the boys are up for a fight for the rest of the season and they showed that," Powell added, before paying tribute to Wales international Church's tidy finish.
"The first goal was a miss hit and the second goal was just class. May be we could have won it but both sides are happy to get a point."
O'Grady's double at least proved to Barnsley manager Flitcroft that his men can score after three games without a goal.
He was reluctant to lay into his men too much after their collapse too, opting to focus on the positives.
"At 2-0 up we fully dominated the game but the game management was poor and they lost composure and that disappointed me," he said.
"But the game management will come with experience and exposure. On the positive side we created a lot of chances in the first half. Charlton are a good Championship team and we have dominated them.
"Our display in the first half was as good as I have seen. The synergy between the defence and midfield was excellent but we have to be more ruthless, as at 2-0 up we felt comfortable."