Brown said: "Portsmouth are the best team at the moment in the division but we were the better side on the night.
"We were in control for the first 25 minutes and the turning point was the penalty because before then we were the team who looked more like scoring and had the better chances.
"At half time, I had a go at some of the lads who hadn't played that well and we pulled a goal back immediately, but we were guilty of not taking our chances which is what has happened for most of this season."