In-form Huddersfield striker James Vaughan scored his ninth goal in as many outings as the Terriers ensured Charlton's wait for points on the road this season continues.
Vaughan's strike on the stroke of half-time set the home side on their way to victory before Lynch's 35-yard thunderbolt gave Mark Robins' side a two-goal cushion.
Addicks debutant Cameron Stewart grabbed an equally fine consolation for his side, but Powell felt Huddersfield just about warranted the points.
"It was a fairly patchy first half from both teams," Powell said. "But conceding the goal when we did right on the stroke of half-time put us on the back foot.
"We responded well, but you can't legislate for a wonder goal really. It was an outstanding goal from Joel Lynch.
"We threw everything at them after that and it was a superb strike and goal for Cameron. We were chasing it and maybe we could have pushed them more.
"But I'm sure Huddersfield will be pleased with how they saw it out. However you earn points in the Championship they are always well earned."