Director Jack Huston on battle behind the first film 'Day of the Fight'

Actor and director Jack Huston’s rich family history in Hollywood did not guarantee him an effortless process when directing and writing his first feature film, “Day of the Fight.”

"I can, without question, say this has been the hardest thing I've ever done,” said Huston, grandson of late director John Huston and son of actor and assistant director Tony Huston.

“It's also still happening. The film hasn't come out yet. I mean, every day is still a fight. It's the fight of the day, not the day of the fight. Every day is a new fight, a new hurdle,” he added.

“Day of the Fight,” distributed by Falling Forward Films, stars Michael Pitt, Nicolette Robinson, Joe Pesci, Steve Buscemi, and Ron Perlman, arrives in theaters on Friday.

Huston’s great-grandfather, Walter Huston, was a leading man during Hollywood’s silent film era. He won an Oscar for the film The Treasure of the Sierra Madre, directed by John Huston, who also won two Oscars for directing and writing that film.

Jack's aunt, Hollywood star Anjelica Huston, and his uncle, director and actor Danny Huston, were also well-known in the industry.

Huston took some family advice when casting the lead, Michael Pitt. Pitt portrays Mike Flannigan, otherwise known by his boxer's name, Irish Mike, as a terminally ill boxer trying to make amends in his life before he dies.

"I take a nice piece of advice I heard my grandfather say, which is ‘90 percent is casting,’" said Huston.

"I wrote every word for Michael Pitt. I knew that it was going to be Michael Pitt. I wouldn't have it any other way. I believe that when you cast an actor, you're giving them the role they own now,” he added.

Huston and Pitt bonded while working together on the HBO crime drama “Boardwalk Empire.”

The film ends with a boxing fight in which Irish Mike knows he isn't going to survive.

"We had a day and a half on the boxing scene, and about other boxing movies, that's a tenth, probably a hundredth of what some other movies have had. But thank God I had Mike (Michael Pitt) as my sort of partner in crime,” the “American Hustle” actor said.

However, Pitt felt he let down the production after asking for a five-minute break during the fight scene.

“I was like, I'm tired," Pitt said. "I didn't condition myself well enough. And then someone told me how long we had been shooting. We'd been shooting for about eight hours. And I was like, oh, I'm fine."