After an early Chris Baird own goal, Fulham rallied to equalise through Damien Duff on the hour-mark before Zamora powered home a free-kick in the 90th minute to take all three points and record his 15th goal for the season.
Birmingham boss Alex McLeish joined the chorus of people currently praising Zamora's form and was another backer for a World Cup spot for the ex-Tottenham and West Ham forward.
"Bobby Zamora was a thorn all afternoon - he caused us a lot of problems," said the Blues manager.
"I think Zamora was the difference. If Fabio Capello is looking for a certain type of forward then Zamora is as good as anyone I've seen at keeping that ball up.
"Like Emile Heskey he's a guy who can bring other players into play and help other people prosper without maybe being prolific."