Daniel Powell scored for the third game in a row while fellow youth-team product Sam Baldock came off the bench to complete victory late on. Paul Benson was sent off for the Addicks at the death.
Robinson said: "It was so important that we kept the momentum and it was convincing in the end. The referee tried to give them extra time and they still couldn't score within that.
"All the decisions went a certain way, although I thought the sending off wasn't a sending off - I think he just reached for it.
"But the most important thing is that we got the result, and not to be talking about the officials. Sam is now contributing to the back end of the season, which is important for him. He started off on fire but he's been injury hit for the last three of four months.
"And Dan Powell is building up a great reputation for himself. He is adding goals to the other assets he has got and he is becoming a big asset for the football club."