Will Smith finally grows up and shows what he's made of, and he's made of better stuff than we've ever seen in fairy floss like Independence Day. Also the deft hand of Michael Mann brings an honesty to the 64-74 years in Ali's life and a stellar performance from Smith and everyone else.

It draws a brilliantly crafted plot from Ali's links to the Nation of Islam, womanising ways and legal problems, and the only criticism I can muster is that the film goes a bit over the edge with the story between fight scenes. It makes the movie feel like a documentary and assumes prior knowledge the audience isn't privy to, often doing so with long, brooding setting of moods.

But Smith has Ali's mannerism, his voice and his face down to a T, and the boxing scenes are the most realistic ever seen on film, no less exciting for it. Mann shows a dexterity with film styles, stocks and textures that make the story all the richer. Voight is unrecognisable under heavy prosthetics as legendary sportscaster Cosell.