Asner plays promoter Frank Bass, who has to juggle the conflicting demands of his champ (Gagne), secretary (Giftos; given Asner's role in the then-popular Mary Tyler Moore Show, her resemblance to Moore is likely no coincidence), new British challenger (Robinson) and, worst of all, a corrupt mobster with a bet on the title bout. The last really sums up the film's main problem: it treats pro wrestling as a legitimate sport, not highly-skilled entertainment. Even when this was made in 1974, the cracks were showing; nowadays, only an idiot would gamble on pro wrestling, leaving a central premise of the film, frankly, implausible.
This crops up elsewhere, most notably a lengthy lecture on amateur vs. professional techniques, which totally ignores the big difference - predetermined outcomes. However, the film has its moments, thanks in part to an interesting cast of more or less well-known supporting characters from the ring world: Superstar Billy Graham, Dusty Rhodes, Ric Flair, Vince McMahon Sr, and Harold Sakata (Oddjob in Goldfinger). But you can tell that dramatic acting is not their strength, so the potential is left largely unfulfilled, and the bouts are filmed in a manner that, for some reason, uses an odd visual style resembling a fisheye lens. It deserves credit for a nice ending, but otherwise, this is of interest only as a period piece.