Pearce was apprehensive about working with Downey Jr

Los Angeles: Australian actor Guy Pearce, who has shared screen space with Robert Downey Jr. in 'Iron Man 3', says he felt nervous while working the Hollywood star.

"I was a bit nervous that he might have been a bit of a firecracker and he was never going to listen to anything anyone said. I thought, 'Wow, this guy's a genius, he's not even going to notice I'm there.' But it was the complete opposite," quoted femalefirst.co.uk while saying.

"And it's not like he's sold out and he's playing some schlocky superhero and he's doing it badly," he added.