The increasing popularity of Mixed Martial Arts as a spectator sport—as witnessed in its cable ratings and Pay Per View events as well as live bouts—will insure at least a core audience for this fight flick, which melds MMA with elements of both “Rocky” and “The Fighter.” But though it’s essentially an astronomically silly formula sports movie stuffed with bone-crunching action, “Warrior” also plays so skillfully as family melodrama that it should connect even with viewers who would never think of watching an MMA match.

The picture—which doesn’t feel as long as its 139-minute running-time—falls into two roughly equal parts. The first introduces a broken family of two brothers and their father, a recovering alcoholic from whose brutal mistreatment the younger son fled with his mother years before. Tommy Riordan, born Conlon (Tom Hardy) returns to Pittsburgh after many years, belligerent and brooding. He decides to train for a recently-announced MMA tournament that will bring a $5,000,000 purse to the victor, and approaches his wizened father Paddy (Nick Nolte)—his wrestling coach in the old days—to train him, even though he still detests the old man for his treatment of his wife, who died miserably after she’d left him.

Meanwhile Tommy’s brother Brendan (Joel Edgerton), an erstwhile UFC fighter turned high school physics teacher, finds himself suspended from his job after the superintendent learns he’d participated in a local MMA bout to earn some extra cash. He needs the money because the bank is threatening him with foreclosure. Though his wife (Jennifer Morrison) doesn’t want him to go back into the octagon-shaped ring, he refuses to do nothing while they and their three kids are tossed into the street. So he persuades his old buddy, famous MMA coach Frank Campana (Frank Grillo), to take him on and get him into the tournament as well. Five million, after all, will cover the mortgage on his modest suburban home for quite awhile. Brendan, it should be noted, is also estranged from Paddy, and hasn’t seen Tommy since his brother escaped with their mother.

It’s inevitable that Tommy and Brendan are going to meet in the deciding match of the tourney. But each of them has to dispatch a number of preliminary opponents before facing off against each other. So the second half of “Warrior” is devoted to the sequence of fights that lead up to the big finale (a real “Rocky Two”). Tommy’s portrayed as the solemn, secretive ex-Marine who just comes out and disposes of the other combatants in record time. Brendan, by contrast, is the ultimate underdog, an over-thirty lightweight who gets pummeled for round after round by his opponents until he turns the tables in one lightning move and wins. He’s obviously the true Rocky of this story.

To make the family dynamic still more dysfunctional, Brendan’s at odds with Paddy too, excluding the old man from any contact with his family. And Tommy, it turns out, blames Brendan for not having joined them when they left home and tried to make a new life. Needless to say, when the boys beat each other to pulp, the experience will bring them together again, and even Paddy will feel a measure of acceptance again. There’s also a subplot about Tommy’s other family, the brotherhood of Marines, which involves both undisclosed heroism and a terrible psychological wound.

This would all come across as ludicrous were the film not so cannily put together. Gavin O’Connor, who directs from a script by himself and two collaborators, works with cinematographer Masanobu Takayanagi to give it a grubby, realistic look in the carnival Atlantic City atmosphere of the tournament as well as in the earlier Pittsburgh kitchen-sink segments. The duo are also well served by editors John Gilroy, Sean Albertson, Matt Chesse and Aaron Marshall, whose sharp cutting of the match sequences make them viscerally exciting (a result abetted by Mark Isham’s pounding score).

And O’Connor is very fortunate in his cast. Edgerton offers an affecting mixture of strength and vulnerability as ordinary guy Brendan, while Hardy demonstrates the intensity of a young Charles Bronson as the tortured Tommy. And Nolte is the epitome of morose dishevelment as Paddy—he’s amazing in a scene when the character falls off the wagon. There’s good supporting work too from Grillo and Morrison, and Kevin Dunn has a showy role as the principal of Brendan’s school, who turns out to be a big UFC fan and joins the fighter’s supportive students—they love their teach—in a big communal audience at the local drive-in to root him on. Wrestling fans will also enjoy seeing Kurt Angle as Koba, the supposedly unbeatable Russian gorilla who—like Dolph Lundgren in “Rocky IV”—turns out not to be invincible after all.

The title of “Warrior” has a double meaning, pointing not only to the skill and determination of scrappy Brendan in the ring but to all the baggage Tommy brings to the ring from his military background (and to their common struggle to reach some family understanding). And that’s characteristic of the entire picture: the individual elements may be contrived and formulaic, but the makers have melded them so artfully that the result is a picture that might lead with its fists, but ends up delivering a surprisingly strong blow to the heart. It’s a cinematic sucker punch, sure, but one that hits home.