HBO made a splash at Cannes with Steven Soderbergh's "Behind the Candelabra," its glitzy, funny, tragic biopic of Liberace (Michael Douglas) by way of his young lover Scott Thorson (Matt Damon). But the premium network also had another, admittedly less sexy film playing at the festival -- Stephen Frears' "Muhammad Ali's Greatest Fight," about the boxing legend's Supreme Court case over his right to not be drafted into fighting in the Vietnam War. No one plays Ali in the film, wisely -- it instead uses real footage of the man while focusing on the behind-closed-doors legal process, with Christopher Plummer, Frank Langella, Ed Begley, Jr. and Danny Glover playing justices. The film's set to premiere on HBO on Saturday, October 5th at 8pm.