Jake Gyllenhaal ended up in hospital after cutting his hand on the set of new movie Nightcrawler.
The End Of Watch star was shooting an intense scene in the thriller and punched a mirror, which then smashed and slashed his hand, reported People.
"Jake flipped out," a source said. "His character was looking into a mirror during the scene and punched the mirror in anger and broke it, cutting himself so bad he had to be taken to a hospital."
The insider revealed the accident came about because Jake was so into character, as struggling freelance crime reporter Lou.
"The scene was emotionally charged and his character was talking into a mirror and he got so into it, he banged his hands against the mirror and it broke and cut him," the source said. "It was all the scene and not because he was mad about anything else."
Jake, 32, received stitches at the hospital and he later returned to the set.
The actor has lost "somewhere around 20 pounds" in weight for the thriller, and recently told E! News that he didn't need to go on any special diet to shed the pounds.
"I can only approach things from a mental place," he said. "Like I'm playing a character who's hungry, figuratively and literally, who's driven in ways to do things and succeed at any cost. And I think that defines a generation in a lot of ways, so I wanted to get there mentally and then have it transform me physically, because I am not one to rely on science as much as I am on just sort of instinct. That's sort of the character."