Powell was given his first coaching role by Nigel Pearson at the Foxes before taking over at the Valley 18 months ago.
"It wasn't me versus Nigel, it was Charlton versus Leicester," said Powell.
"I take satisfaction from winning the game. It was a terrific game, end to end, we were clinical in the first half and they were in the ascendancy in the second.
"They put us on the back foot and could have snatched a draw but we threw our bodies in the way."
Charlton welcome Hull City to the Valley on Saturday.