A star in the making. A troubled young talent. A charismatic promoter and a wise veteran fighter/manager.

Documentary filmmakers Michael Tucker and Petra Epperlein hit the jackpot when they embarked on "Fightville." They just didn't know it at first, starting the project almost by accident.

Known for war documentaries like "Gunner Palace," the filmmakers turned to mixed martial arts after one of the soldiers they had met invited them to Louisiana in 2008 to watch him in an amateur fight.

They saw several fights cards and went back to their producers.

"'We think there's a film in this. Nobody has done a correct film about this subject,"' Tucker recalled telling them. "And we just started."

The resulting 85-minute film airs next Thursday, Friday and May 3 at Toronto's "Hot Docs" festival.

"Fightville" arrives in Toronto the same week as the UFC does for a record-breaking show before 55,000 at the Rogers Centre.

The film, named after a neighbourhood in Lafayette, serves as a timely backgrounder to that spectacle, offering a look at the demanding, often brutal life young fighters have to live to follow their dream.

Tucker and Epperlein weave several stories together, showing the rise of Dustin (The Diamond) Poirier -- a rising star who was on one of the first cards the filmmakers saw -- and training partner Albert Stainback's detours.

Pulling the strings are Tim Credeur, a veteran fighter and manager who is a Yoda-like presence in the movie, and charismatic local promoter Gil (The Thrill) Guillory.

Credeur said he cried "a bunch of times" when he watched "Fightville" for the first time.

"I work hard at what I do but so much of what I do and who I am is behind closed doors," he said in an interview. "People don't know how hard we work and people don't know how difficult the life of an aspiring mixed martial artist is. How arduous and how gruelling it can be.

"There's very little pay involved with it and there's a whole lot of sacrifice and a lot of bumps and bruises. . . . It was very very enlightening, even for myself, to see what we actually do do every day."

Poirier (9-1) is the star of the show, an unassuming but driven fighter who is making the final steps of a journey that will take him to the big leagues.

Stainback (1-1) is the troubled talent, struggling with his life outside the gym but still burning brightly. The young fighter emerges for his first pro fight, beating his chest and wearing a bowler hat to the music of "A Clockwork Orange."

Credeur (12-3) tries to mentor both, sometimes using tough love. When Stainback skips the gym for several weeks, he has to pay the price.

Credeur puts him in against Poirier and tells his young star not to hold back. Stainback takes a beating, and then thanks his training partner for the bruising lesson.

"We have responsibilities to each other because we can't train without each other," explains Credeur, who hands another fighter a similar beating for the same reason.

"Tim Credeur is something right out of a movie script," said Tucker. "He's just kind of the ultimate trainer.

"Everything that the guy says is quotable. He's the sort of person who wakes up every morning and tweets a philosophical quote from Bruce Lee or from Nietzsche or whatever. He's just perfect."

"Fightville" shows Poirier in three fights with the last, a June 2010 bout in Montreal, deciding whether he will get a contract with a bigger organization.

"That final bout in Montreal was incredible," Tucker said. "I mean Dustin literally turned to me and he was like 'What do you want, boss?' I was like 'I guess I'll take a knockout' and the kid went out there and he just knocked the brakes off that kid.

"That was one of those moments where you go 'You cannot write this, you cannot pay for this, you couldn't design it any better.' He really went all the way and proved himself."

Said the soft-spoken Poirier: "I'm lucky to have these moments of my life caught on tape."

The film is the work of Tucker and Epperlein, who are married, sound mixer C.J. DeGennaro and composer Alex Kliment (whose day job is as a Brazil-based reporter for the Financial Times).

It is beautifully shot with memorable images -- shot from behind, a fighter pulls a curtain aside and pauses before walking through smoke towards the cage, ring girls gyrating in the cage in slow motion, Poirier working out or ringing water out of his clothing as he cuts weight.

Producers may have expected a documentary on a violent sport. And while there are a few bloody fight scenes, "Fightville" offers much more.

"What we came back with was really a film about a sport, and a film about what it takes to be the best in something," said Tucker.

The 22-year-old Poirier, who says martial arts gave him much needed direction in life, continues to prove that. Tucker recalls sharing a hotel room with the fighter at a recent film festival. Before going to sleep, Poirier put on an oxygen monitor.

"He actually shoved tubes up his nose while he was sleeping so that his oxygen levels could be monitored, so that a custom-made breathing apparatus can be made, so while he's sleeping, his muscles are replenished correctly," Tucker said. "Who would think that that kind of science is being applied to a sport like this?"

Poirier eventually signed with World Extreme Cagefighting, which was then purchased by the UFC, the sport's leading promoter. And at UFC 125 on Jan. 1, he upset featherweight contender Josh (The Fluke) Grispi.

His next fight is against Rani Yahya on June 11 in Vancouver at UFC 131.

Credeur, whose fighting career was put on hold, is due to fight Ed (Short Fuse) Herman on a UFC televised card June 4.

As for Stainback, Credeur just got him a job in a restaurant and he is back in the gym.

"Dustin's worrying about his career and I'm worrying about it as well. We've got a big fight coming up for him," Credeur said. "But I'm just as worried about Albert being able to pay his rent."

For Credeur, "Fightville" is just part of their story.

He sees a title down the line for Poirier, given his talent and unwavering commitment.

"There's only one future for a person like that and that's to be a champion. Maybe there's going to be some roadblocks in the way and maybe there's going to be some hiccups and some difficulties, that's the path of any great champion.

"But one way or another, at the end of Dustin's life, he will definitely have been one of the greatest mixed martial arts champions that we know. And it's more because of what he chooses to do with his talent than it is because of the talent he possesses."

The future is murkier for Stainback.

"Albert could be amazing," said Credeur. "Albert is also very very talented, but that work ethic, that dedication to his destiny, that focus is lacking. There's other things in his life that seem to sometimes take precedence, things that at 33 years old I know are not the type of things that you need to be focusing your time and energy on. But at 24, 25 years old, they seem so important.

"Albert definitely will have a good career in mixed martial arts but until he finds the kind of determination that Dustin has, it's going to be very difficult for him to get above the local level."