Pulitzer Prize-winning playwright and filmmaker David Mamet has returned to the enigmatic style of "The Spanish Prisoner" and "The Winslow Boy" in his latest film, "Redbelt."

Anchored by a powerful and nuanced performance by Chiwetel Ejiofor, Mamet's latest writing and directing effort is a compelling drama about the world of martial-arts fighting.

Though the dialogue is perhaps not as potent as in his finest work, it's still much crisper and sharper than most movies set around fighting.

Ejiofor plays Mike, a jiujitsu instructor who has stayed away from prizefighting because he believes "competition is weakening." His much more practical wife, played by Brazilian actress Alice Braga, scoffs at his choice to operate a self-defense school with a samurai's code of integrity: "You're too pure to compete, too pure to make money," she accuses him.

But an accident involving a distraught lawyer (Emily Mortimer) and a compassionate police officer (Max Martini) leads to events that threaten to derail his life.

Mike is forced to enter the ring to pay off debts and re-establish his honor. He must deal with a crooked promoter (Ricky Jay) and a sleazy agent (Joe Mantegna), after a seemingly chance encounter with a self-absorbed movie star (Tim Allen in an intriguingly dark role).

This is a departure for the very talented Ejiofor. His muscled physique, soulful eyes and expressive face are perfect for the role. He can speak volumes saying very little. The rest of the ensemble also is well-cast.

The film is at its best when dealing with human interactions and motivations and drags once it gets into the arena. But its vivid cinematography by Robert Elswit ("There Will Be Blood") is a highlight.

Mamet, who has a purple belt in jiujitsu, clearly is fascinated by the philosophy underlying it, which explains such Eastern-influenced exchanges as: "You train people to fight?" "No," Ejiofor responds. "I train people to prevail."

He explains to Mortimer: "Everything has a force. Embrace it or deflect it. Why oppose it?"

It's certainly not Mamet's signature rapid-fire dialogue, but it's an intriguing and engrossing departure.