Duff scored the equaliser while Bobby Zamora scored the winner to make it 2-1 to Fulham.
“The goal was alright but it was more important that the team managed to get back into the game more than myself adding to my goals tally,” Duff told the club’s official website.
“Whoever scored it was an important goal.
“Of course, it is always nice to score and as we know Bobby [Zamora] went on to score the winner which made it a good day for us.
“They [Birmingham] are a good side and when they go in front like they did against us they usually don’t let that lead slip – so that made the victory very satisfying.”