When Downey Jr was about to punch Zach Galifianakis

Updated: Nov 03, 2010, 12:45 PM IST

Los Angeles: 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.