A few weeks before his death, Michael Clarke Duncan was training in a boxing ring with his co-star and director Kent Moran for their new movie, "The Challenger."

"We were just training with him and he actually does a lot of physical things in the movie as my trainer, so [his death] sort of caught us all by surprise. It was very crazy," Moran told Headlines & Global News in an exclusive interview.

Duncan suffered a heart attack on July 13, 2012, shortly after completing his scenes on "The Challenger." He died on Sept. 3, 2012 at age 54.

Moran cast Duncan to play boxing trainer Duane who helps a struggling auto mechanic Jaden (Moran) get into fighting shape so he can earn money for him and his mother (S. Epatha Merkerson) to move back into their Bronx apartment. When Jaden starts winning his bouts, he attracts the attention of a basic cable network that decides to make a reality TV show called "The Challenger" that will follow him all the way to the heavyweight title.

The film has already garnered several accolades, winning the Audience Award at the Gasparilla International Film Festival, the Palm Beach International Film Festival and the Nashville Film Festival.

"We've definitely been pleased with the audience response," Moran said. "People seemed to be engaged by Jaden's journey and they really get behind [him]. A lot of the time, the audience starts actually cheering as if they're there. That's the kind of environment I wanted to place them in."

The first-time director is also excited for audiences to see Duncan more of a leading role and in "a way they haven't seen him before."

"We had a limited budget so we did limited takes to move fast. Every single take he would just come out and be great and didn't need much direction," Moran said. "The thing I loved about Michael was when the take was over he'd just keep going and I'd let the cameras role. I had so much to work with, he was improvising constantly. It was all good. It was all being his character."

Duncan's booming voice on camera was clear enough that Moran didn't have the problem of re-recording any of his dialogue. His only challenge was to honor his late co-star properly with the best film he could deliver.

"It could have been a lot worse," Moran said. "When he passed, it encouraged us to just take it up to another level of making it as good as it could possibly be before we put it out there."

"The Challenger" still needs a distributor, but the real cause of delay was getting the best visual effects for the movie. "I really wanted to make sure that the crowd looked real and felt real," Moran said.

The actor-director also made sure he looked real as a boxer. He trained for seven months at the Wild Card Boxing Club in Hollywood, Calif., the same gym that Manny Pacquiao used before his bout with Floyd Mayweather.

"I really learned a lot about boxing during that experience. I wrote my direct experience with my trainer there into the script to make it as real as possible," Moran said. "When we were in New York, the training was quite rigorous. You literally run five miles every day before shooting for 12 hours and then come back and do it again."

Moran wanted to steer clear of the mixed-martial arts fighting that has become popular in the last few years. He described boxing as "more traditional in America" and an athlete's story that the audience can more closely relate to.

"I think in a lot of sports movies, especially boxing, you have the physical journey in the sport and that coincides with the character experience," he said.

The boxing enthusiast grew up on movies about the sport as well as stories of his great-great uncle's boxing career, which drew Moran to the topic.

"He fought great fighters. He even fought at Madison Square Garden," Moran said. "He definitely won more than he lost but he certainly had a lot of great bouts. So that sort of family tradition steered me toward that goal."

Moran, who wrote the screenplay eight years ago, also wanted to explore the world of reality television in the movie. He compared the film's fictional show, "The Challenger," to Sylvester Stallone's show "The Contender" that aired on NBC and the documentary that Pacquiao filmed in the lead-up to his big Las Vegas match.

"The whole show is trying to get America behind this underdog and he ends up becoming this symbol for the Bronx," he said about his character's reality TV journey.

The movie incorporates a lot of the Bronx including the famous Willis Ave. Boxing Gym where many of Jaden's mid-level fights were filmed. Moran also had local musicians write songs for the soundtrack.

"There's a lot of great music that these guys came up with so I think the soundtrack will be really cool," he said.

"The Challenger" will screen at the Dances with Films festival in Los Angeles on May 28.