Downey Jr. thought Galifianakis was a crazy fan!

LOS ANGELES - Hollywood funnyman Zach Galifianakis escaped getting punched by his “Due Date” co-star Robert Downey Jr. when he mistook the former for a crazed admirer.

The two rub shoulders in “The Hangover” director Todd Phillips’ forthcoming outing “Due Date” that releases Friday worldwide.

“Before we started shooting, I was down in Venice and some weird guy walks by and goes, ‘Hi, I think I’m doing a movie with you and Todd Phillips’. I thought, ‘I might have to punch this guy’. And then I realised, ‘Oh my god, that’s Zach’. We have definitely come a long way since then,” Downey Jr. said in a statement.