"The Fighter" is a great, gutsy boxing story, a knowingly detailed, compelling, often very funny look inside the lives of underdogs battling for respect. The film's title could apply to every significant character onscreen.

The film's structure is evasive, but it hangs together nicely. The rambling opening scenes, in which the characters mug and strut for an HBO documentary crew visiting their hometown, are important in setting up what follows. Mark Wahlberg plays real-life fighter "Irish" Micky Ward, a 30-year-old contender from blue-collar Lowell, Mass. He's a modest guy, a road paver with a busted marriage, but in the ring, he's the rock of Gibraltar. Rough around the edges, full of potential and consistently flashing hints of greatness. Micky looks like he could follow in the footsteps of his older half-brother, retired pro Dicky Eklund, who once went the distance against Sugar Ray Leonard.

Some footsteps. Dicky, who works on the same road crew as Micky, swaggers down the sidewalk receiving greetings and salutations from the townies like royalty. He's affectionately called "the pride of Lowell," but in truth he's a punch-drunk idiot savant. Dicky is a loose cannon, a crackhead oblivious to the destructive choices he makes. You can see why he'd thrive in the controlled chaos of boxing. In the real world he hasn't a clue. Micky and Dicky are polar opposites. Dicky loves his little brother but envies him, nurtures him with savvy coaching advice while undermining him with erratic, unreliable behavior. The reluctant mentor-irrepressible pupil story has been done a million times before in sports movies. This one sets the formula on its head.

In the role of Dicky, Christian Bale proves he is one of the most talented and interesting actors of his generation. Gaunt-cheeked, wild-eyed and sizzling with unfocused energy, he makes Dicky an unforgettable goofus-hustler. And that is no small accomplishment in a film swirling with so many vivid characters, so much life and complication. "The Fighter" is like a big, unruly party, a harmonious cacophony of overlapping voices and competing agendas. The ensemble scenes, with Melissa Leo as the brothers' hard-shellacked ma, Alice, and her brood of a half-dozen smart-mouthed daughters, leave you feeling alternately exhilarated, baffled and overwhelmed. Alice, a domineering alpha-cougar, slings plates at her current husband when she's peeved. You can see why Micky and Dicky felt at home in the ring; they learned to duck early.

As he battles his way up the ranks, soft-spoken Micky acquires a girlfriend and champion in Charlene (Amy Adams, proving that she can play a brassy barmaid as well as a Disney princess). In Charlene's first uproarious encounter with the family, the women size her up with withering sneers and call her "an MTV girl" -- a wild thing who thinks she's better than they are. His new relationship forces Micky to recognize that he may have to fight his way free of his smothering, demanding clan if he's to succeed. But cut off from that taproot of family loyalty, does he have a shot?

If you have seen many boxing pictures, or know Micky Ward's real-life story, you know the answer, but the film keeps you gripping the armrests until the final punch is thrown. Director David O. Russell ("Three Kings") has created a casual masterpiece, an irresistibly enjoyable film that makes everything else in theaters feel like yesterday's news. It's one of the greatest movie experiences of the year.

ccovert@startribune.com • 612-673-7186