The Addicks came from behind to beat Bolton 3-2 on Saturday and Powell was pleased to follow up that memorable victory with a point at a promotion-chasing side.
"I'm really pleased, it was a great point for us," said Powell.
"Brighton is a tough place to come and I knew we would have our hands full, but I felt we had our tactics right.
"Our shape was right and the point and a clean sheet is really pleasing for us, following our win last Saturday."
Charlton have performed well on their travels this season and Powell added: "Our away record is something to be proud of. It gives us real heart and confidence in our remaining six games.
"We have got 51 points now and there are 18 points still to play for. We need to carry on the decent form we are in and finish as strongly as we can.
"Come the end of the season, this point could make a difference. Going into the game we would have taken a point and a clean sheet.
"In the end we could have even nicked it and (Charlton goalkeeper) Ben Hamer also made a crucial save at the death."