The true strength behind Michael Mann’s Ali has to do with the performance of Will Smith. As presented on film, Cassius Clay (who became known as Muhammad Ali) shows charisma, an otherworldly sense of humour and a brooding quality which may not endear him to every filmgoer.

The picture starts off brilliantly with a montage featuring Clay (Smith) as he trains for his big fight against heavyweight champion, Sonny Liston (Michael Bentt). Half the pleasure in watching Ali relies on not knowing too much about the plot beforehand. Within the entire spectrum of this icon’s life, Mann has made an epic masterpiece that redefines how a filmmaker stages boxing scenes and how the audience experiences them.

Despite emphasis on fighting, Ali’s role as a pacifist constitutes a major part of the film’s backbone. His refusal to enlist in the Vietnam conflict, given his “conscientious objection basis,” proves to be only the first hurdle in a life-long struggle for social balance. When Malcolm X (Mario Van Peebles) tells him about the bombing of the Birmingham church, the actor dictates the pace of the editing and not the editor. By holding on a close shot of Malcolm X for a considerable length of time, the performance is allowed to breathe. No amount of cut and paste work would have been as effective as this method of not cutting. Also, letting the moment be its organic self is the mark of a truly marvelous editing style. In this scene, as in many others, editors William C. Goldenberg, Stephen Rivkin and Lynzee Klingman adopt a disciplined approach that results in maintaining the best overall flow for the movie.

Weighty issues can run amok without a sure and steady hand at the helm. Mann’s approach dictates the idea that Ali, definitely a social pariah in his day, chose the path least taken because he felt it was the right thing to do.

Putting on the pounds as well as training vigorously can only make up a small fraction of what it takes to become Ali. Smith, with his rapid-fire insult humour and on-the-nose ideologies, inhabits the role like his life depended on it. Whether it means sparring verbally with TV sports commentator Howard Cosell (Jon Voight) or trying to manage his unstable “inspiration,” Drew Bundini Brown (Jamie Foxx), Smith shines all the way through. For perhaps the first time, his convincing presence goes beyond surface details and into the realm of true depth.

Most critics and/or social historians hold up Martin Scorsese’s Raging Bull (1980) as the definitive boxing film. Yet, if you only watch the first fight between Clay and Liston in Ali, it becomes apparent that the authenticity here feels very different. Using the Elmo camera, cinematographer Emmanuel Lubezki aims for total immersion inside the boxing experience. Every punch rings true. Normally, actors are inclined to shadow-box, a safer alternative, which looks and feels false. This was the problem with Raging Bull -- not to mention the limited running time for the boxing scenes. In my opinion, Ali achieves a rare position in the pantheon of sports movies... as the finest one ever made.

(Released by Columbia Pictures and rated “R” for some language and brief violence.)