SIDELINE CUT:JUST AS the dust has settled on Obamarama and the great leap forward for race relations in America, there comes a sad and spellbinding boxing documentary that bears testimony to the complexities of being black and American. Thrilla In Manila was shown with little fanfare on television during this week.

It caught up with Joe Frazier, the former heavyweight champion whose boxing career and whose life, in many ways, has been distilled and frozen in the images from that soupy morning in Kinshasa when he engaged Ali, his nemesis, in what some have described as the most brutal bout in boxing history (Although this can hardly be true when other men have lost their lives in the ring).

It is always somehow shocking to see sports icons from an earlier age as they are now. When performing at their best, they appear almost superhuman and because their greatest days are kept fresh in our minds and on television reruns, we do not expect - or want - them to age.

These days, Smokin' Joe is a dandified 64-year-old and lives in a dated bachelor's apartment located over the boxing gym he runs in Philadelphia's notorious Badlands. In his heyday, as heavyweight champion of the world (during Ali's period in forced exile for refusing the US army draft) Frazier had the power to summon a meeting with then president Richard Nixon in order to persuade the powers that be to grant Ali his licence back.

The days of million dollar fights and instant connection to the very citadel of the American establishment have long passed for Frazier and in so far as he is remembered at all, it is because he has been incorporated into the Ali myth; a key figure but ultimately just one of the many support players in the sprawling, messy theatre in which Ali was always the main, towering presence.

It has often been acknowledged that Ali's barbed and persistent taunting of Frazier was one of the most overt examples of the cruel streak that ran contrary to his warmth and humour. Ali, of course, gloatingly referred to Frazier as an "Uncle Tom", a pawn in the white man's system and, in the run-up to Kinshasa fight, repeatedly described his opponent as "that big, ugly gorilla", culminating in a surreal and unfunny episode where he spars in the ring with someone on a gorilla costume.

What the makers of Thrilla In Manila recognised was that nobody had fully explored the effect that those long and unique few weeks in the Philippines have had on Joe Frazier, the man. In the years since the fight, Ali's fate saw him transformed from perhaps the single most dazzling and magnetic public figure of the 20th century into a greying man stilled and silenced by a wasting disease who has accepted his lot with a grace that is almost unbearable to behold for those that knew him in his days (and nights) of perpetual incandescence.

What makes this documentary so bleak and powerful is that is apparent from the outset that Frazier's attitude to Ali has not been at all softened by the years. He is by and large a contented man but when it comes to that one episode - a central event in his life - he is ferociously bitter at the way Ali treated him, at being the butt of his jokes and, perhaps, at having been forced to stay sitting by his trainer Eddie Futch after 14 brutal rounds when both men had meted out so much punishment they were hanging on to the last threads of the athlete's survival instinct (Ali collapsed in exhaustion moments after rising from his stool to celebrate).

This revelation went against the prescribed tradition of sports: that in their dotage, the most livid of foes mellow towards one another and doff a cap to the good old days. Frazier, though, cannot let go of the humiliation that Ali, by then an absolute master of the adoring American and international press that came globetrotting in his shadow, put him through day after day.

The most shocking realisation is that he fervently believes Ali's deterioration through Parkinson's Disease is a deserved sentence for the lippy, taunting streams of consciousness through which Ali would amuse himself and the world. Joe was regularly the butt of his jokes and his socio-political lectures. Here, unlike the acclaimed When We Were Kings, often acclaimed as the best sports documentary ever made, the audience is forced to see Ali through a less flattering prism.

Here, there is no Norman Mailer or George Plimpton to attest to Ali's irrepressible charm. Instead, the audience is confronted with Ali's narcissism and what Frazier saw as a betrayal of a friendship and a fundamental breach of brotherhood.

It was Frazier who had supported Ali during his exile - sometimes financially - and who lobbied to get him the reprieve he so desperately wanted.

Somehow, Ali translated that into proof that Frazier - who was refused the right to cash his cheque in his hometown in South Carolina when he was champion of the world - was part of the "white" system, the "Other" side that he persistently denounced.

Ali, so independent and enquiring, was always desperately trying to understand and explore how he fitted into the American system and he did this the only way he knew how, through public discourse - be that through his mock-glowering exchanges with Michael Parkinson or his Nation of Islam statements.

Frazier was simply a 1940s-born slave-descendant raised in what was, ultimately, a system of apartheid, trying to get along and to thrive in a system governed by white men. He hardly deserved to be pilloried for that. When they boxed in Kinshasa for the third time, it was with a ferocity that bordered on hatred and the footage remains breathtakingly violent.

After that fight, Ali boxed past the point of being punch drunk, made and lost a tonne in endorsements, became simultaneously ill and a global icon and made his peace with the world. Joe Frazier's name was pushed off the news pages, the money got spent but he kept his wits and his health.

On his mobile phone now, his message revels in that fact with a mocking message that plays on Ali's "floats like a butterfly" mantra, glorying in the fact he has all his faculties while Ali, the beautiful one with the motor-mouth, cannot dance around a ring any more or deliver any more taunts.

Made by the same team who produced Touching the Void, the drama documentary about the deadly escapades of mountaineer Joe Simpson, Thrilla in Manila places a dark veil over perhaps the most romanticised and heavily studied era in sports history.

There is, of course, a supreme and obvious irony in that even as Smokin' Joe takes a small pleasure in the fact his old adversary has become trapped in his own mind, he too is imprisoned by the hold a fight of some 30 years ago has maintained on him and by the fact that even now, he is itching for that 15th round. In a New York Times interview eight years ago, Ali acknowledged he regretted the things that he had said and pleaded he was just trying to promote the fight.

The director of this film, John Dower, eventually persuaded Frazier to sit down in his living room and watch that defining fight for the first time. It is deeply unsettling to realise an encounter that has been celebrated by generations of boxing fans had, until this moment, never been viewed by one of the protagonists.

For most of the film, the camera stays on Joe Frazier's gaunt face, his mouth hanging open as he stares transfixed at the Technicolor images of the fight that he has been playing and replaying in his mind all these years. At one stage, Ali comes at him with a barrage of such aggression that the commentator excitedly predicts that Frazier must hit the canvas.

"Never went down, though," Joe murmurs with a faint smile of jubilation.

Thrilla In Manila is the most unforgettable sports film you could ever hope to see.