"Coming off the bench and scoring the winning goal is a dream come true. I was pleased with that, but the main thing was getting the three points," he said.
The win stretched Charlton's unbeaten run to 11 games and took them level on points with second-placed Norwich and just three behind leaders Leeds.
Wagstaff added: "We've been doing really well - we've gone 11 games unbeaten now and it's good to keep that going.
"But all we can do is concentrate on ourselves and see what we can do. We can't really look beyond that. If we make sure we win our games, we don't need to worry about anyone else."