The sheer savagery of the fights is the selling point of “Avengement,” kickboxer turned actor Scott Adkins’ latest thriller with stuntman turned director Jesse V. Johnson.

It’s a step up from their “Debt Collector” punch-em-up, more polished.

But if you come for the fights you have to stay for the fights. It’s just that there’s an awful lot of cockney trash talk in the endless ENDless flashbacks in this static, almost stage-bound convict-out-for-revenge tale.

Adkins is Cain Burgess, an MMA fighter who failed to throw a fight, way back when. His brother Lincoln (Craig Fairbrass), a London loan shark, was among those most burned by that blunder. The chit that brother Linc called in was a little crime he expected “baby bruvva” to do. And that’s how Cain got nicked, as they say.

Belmarsh Prison, “The Meatgrinder,” is where the fighter hardened into a kill-or-be-killed survivor. And when he escapes, who’s he looking for? Big bruvva, and big bruvva’s whole gang.

You can see why Johnson (“The Hitman Diaries: Charlie Valentine” was the first film of his I noticed) would want to mess around with story structure to make this straightforward punch your way to “Avengement” more interesting. But parking most of the action in a pub/mob-club where Cain holds assorted villains hostage while he laboriously tells them how he got all these scars on his face and body is a blunder.

“Avengement” is all action beats — a delayed account of how Cain escaped, every police beating, every prison riot started as a cover to kill him on the catwalks, in the cafeteria, in the yard — and thick-accented Cockney exposition between bad guys, threats, insults, profane dismissals.

And as much as many of us enjoy the slang — “You and your silly ‘panto’ (pantomime, a British holiday storytelling tradition), a bloke having his first pint in years engaged “in some wishful drinking,” as he tells the story of how “the prodigal bruvva returns.”

The fights are furious and occasionally logical, although there’s an awful lot of “You have YOUR turn with him before I take a swing” nonsense you see in brawling movies.

And some of the humor, much of it coming from the poseur among the mobsters (Thomas Turgoose of the skinhead drama “This is England”), brings a smirk, especially when Cain’s storytelling runs on and on and, well, they’re in a pub and yes they had several pints before he pulled a sawed-off shotgun on them.

“To be fair, NONE of us had planned on being held hostage today.”

Adkins is better here than he’s been in other leading man roles, although casting his American “Debt Collector” co-star Louis Mandylor (as a cop) just reminds us the Brit has fists of fury, hardened good looks and not a lot of screen charisma to go with them.

He’s acted and earned his way into Jason Statham C-movie territory, and “Avengement” invites a comparison with the “Hobbs & Shaw” star that still does Adkins no service. He’s still dull every time he stops swinging his fists.

Still, if what you’re looking for it fists of fury, he can provide them. And if you’re looking for signs that a guy who is playing heavies in small roles in big budget pictures is growing as a performer, that he and Johnson have gotten better since “Debt Collector,” just not all that much, “Avengement” is going to be your kind of movie.

MPAA Rating: unrated, graphic, bloody violence, profanity

Cast: Scott Adkins, Craig Fairbrass, Thomas Turgoose, Nick Moran, Kierston Wareing and Louis Mandylor

Credits: Directed by Jesse V. Johnson, script by Jesse V. Johnson, Stu Small. A Samuel L. Goldwyn release.

Running time: 1:27