TORONTO -- Playing notoriously hot-headed tennis legend John McEnroe on the big screen was "quite cathartic" for Shia LaBeouf.

"To watch it now is something I'm very proud of," LaBeouf said at a press conference Thursday before the movie's world premiere at the Toronto International Film Festival.

"I'm very proud of the movie and I think it expresses something I feel deeply."

LaBeouf stars opposite Sverrir Gudnason in "Borg/McEnroe," a film that recreates the match between McEnroe of the U.S. and Sweden's Bjorn Borg at the 1980 Wimbledon Championships.

As the film shows, McEnroe was known for his expletive-laden outbursts that got him into trouble on the court, while Borg was portrayed in the media as a more calm player.

In one scene, McEnroe remarks on how people talk more about his behaviour than his tennis.

LaBeouf, whose personal life and public antics have also made headlines over the years, said he identifies with that aspect of McEnroe's life.

"This is another parallel that I feel with him, for sure. It's part of the cathartic feeling of the film for me."

McEnroe is misunderstood, said LaBeouf.

"I think he's a tactician. He really added something different to the game," he said.

"When he entered the game, it was baseliners, it was a power sport and Borg was the king of that. (McEnroe) brought touch and feel and a sensitivity to the game that wasn't there before.

"It's not just screaming rage. He used rage as a tactic to throw people off and he manufactured his intensity to hype himself up. In that way, he's an artist."

This film marked the second time LaBeouf had been asked to play McEnroe. He said the first script was a satire and "wasn't treating McEnroe's story with a whole lot of respect or any empathy at all, he was just sort of a clown, screaming shrew."

He was attracted to this particular project because he was a fan of director Janus Metz's work and was moved by Ronnie Sandahl's script.

Gudnason said they started training six months before shooting. He trained two hours a day and "had to live that life as an athlete to understand" his character.

LaBeouf said the action scenes were carefully scripted and choreographed to resemble the famous match.

"It's a bit like watching 'Amadeus.' He's like the Mozart character," LaBeouf said of McEnroe. "So I watched 'Amadeus' a lot."

Although he spent countless hours learning about the sport, LaBeouf felt he never truly learned how to play.

"We rehearsed things like a ballet, including (McEnroe's) outbursts. I would literally play them on a screen right before we would film and look at where everything was, and it was very paint-by-the-numbers in a way," LaBeouf said.

"You could've given me 20 years and I would've never played like McEnroe.... I started learning it like a dance, I never actually played tennis, it was something different."

Metz said some moviemaking "magic tricks" were used to "sell" the actors' performances, given they had never played tennis prior to the film shoot.

Ultimately the story is "about how two people individually were able to drive themselves to the edge and beyond in order to achieve something extraordinary," said Metz.

LaBeouf said he hasn't met McEnroe but would like to. Gudnason recently met Borg, whose son has a part in the film.

Though they were depicted as rivals, the two had a mutual understanding, said the stars.

"In some ways you could say this is a portrait of two drug addicts," said Gudnason. "Their drug is tennis, their drug is intensity."

"Borg/McEnroe" officially kicked off TIFF on Thursday, which runs through Sept. 17. Canadian tennis phenom Denis Shapovalov was set to walk the red carpet along with the film's stars for the gala screening.

About 340 films will screen at this year's fest, which is a smaller number than in recent years -- a result of a TIFF mandate to trim the overall number of titles by 20 per cent. Organizers said they made the changes in response to feedback from audiences, the industry and the media.

Among the first celebrities to arrive in Toronto for the fest were Charlie Hunnam of "Sons of Anarchy" fame, who stars in "Papillon" with Rami Malek of "Mr. Robot," Armie Hammer of "Call Me By Your Name," and supermodel and musician Grace Jones, who is promoting a documentary about her life.

Other films in the lineup include "Suburbicon," directed by George Clooney, Darren Aronofsky's "mother!" starring Jennifer Lawrence and Alexander Payne's "Downsizing."

About a third of the films in the lineup are directed by women, including Angelina Jolie's "First They Killed My Father."

Other stars expected to attend the festival include Denzel Washington ("Roman J. Israel, Esq."), Jessica Chastain and Idris Elba (both of "Molly's Game") and Steve Carell and Emma Stone (co-stars of another tennis movie, "Battle Of The Sexes").