Hamilton struck the opener from 16 yards off the far post after a thrilling run down the left and afterwards said: “I have been told by the manager to shoot a lot more when I can. I saw the gap, took it and luckily it went in.
“When I saw it going towards the post I wasn’t sure if it would rebound out or hit the net. Thankfully it hit the net.”
He added: “Everyone put in a really good shift. Charlton are a really good team up there in the top six in League One.
“They can play football and we defended excellently today as well as creating chances going forward.”
However, Charlton forced a replay though Toby Stevenson’s 73rd minute equaliser which replays showed was offside.
“You could see by the reaction of some of our players that he was offside. He was standing on the line before the ball even came in,” said Hamilton.
“We did the best we could, but we have to go down to the Valley now and try to win it down there.
“It gives us a lot of confidence to go back into our league now and try to beat teams week in week out.”
Hamilton tried to burst clear near the end only to be wrestled to the ground by Billy Clarke.
“The gaffer said it was nearly GBH. It’s frustrating as I was nearly through if I’d got past him,” he said.