Warning to Dwayne Johnson fans: “Fighting with My Family” does not have Dwayne Johnson in a starring role. Oh, he’s in the film, playing himself, both as Dwayne Johnson and his wrestling character The Rock. But it’s a decidedly minor part.

It’s a wrestling movie, one that looks into two very different sides of the sport: The smalltime scrappy World Association of Wrestling (WAW), based in Norwich, England, owned by the Knight Family - dad and mom and two sons and a daughter - and the glitzy, internationally renowned WWE. The crazy thing about this low-budget, full-of-heart movie is that it can be enjoyed by both pro wrestling aficionados and non-fans. The presentation of its true story is gritty enough in showing how tough and competitive the business is, which will please those folks who regularly watch “Monday Night Raw,” and is entertaining and educational enough to capture the fancies of viewers who don’t, in the words of the late, great Gorilla Monsoon, know the difference between a wristlock and a wristwatch.

Within the WAW, dad is Ricky Knight (Nick Frost), a former criminal who did his share of jail time, then had his life saved when he discovered wrestling. Mom is Julia (Lena Headey), also with a shady past, also getting her life turned around when she met Ricky, and got into the wrestling game. Their older son Roy, a wrestling prodigy, isn’t in the film much because at the time of the story, he was in jail. The focus here is on the other two Knight kids - the up-and-coming wrestler Zak (Jack Lowden) and little sister Britany (Florence Pugh), who joined the family business as a lark, but soon fell under its spell.

The WAW is just eking by, and dad is convinced that both Zak and Britany are good enough to get into the WWE. He keeps sending videotapes of his kids to the American offices and leaving messages with Hutch Morgan (Vince Vaughn), a no-nonsense WWE scout and trainer who’s always on the lookout for the next big thing. His efforts pay off when he’s told that Zak and Britany have been invited to try out for the big leagues when WWE comes to London for a “Smackdown” taping.

With that part of the story working as the first main event of the film, an entryway opens up into side stories galore. Zak is dating Courtney, who comes to dinner at the Knight home with her parents (dad is played by writer-director Stephen Merchant), neither of whom knows a thing about wrestling, which leads to some good comic moments. The wrestling audition goes well for Britany but not for Zak. The Rock gets the first of his cameos and shows, through the prism of a promo (an unscripted chunk of dialogue in which a wrestler goes nuts - in character - into a microphone), how he became a star.

But all of this is just a prelude for what happened to Britany when she headed to Florida for developmental training and changed her ring name to Paige. Wrestling, of course, is a soap opera played out by actors with a great deal of athletic prowess. The film traces Paige’s path from her family’s small outfit to superstardom, and how she dealt with grueling workouts, the lonely life of being an outsider in a different world, and the constant nagging feelings of self-doubt, of wondering if she made the right decision to come to America and leave her dispirited brother behind. Merchant’s script features lots of nicely wrought back and forth looks at the situations each of the siblings is going through, and both Pugh and Lowden play them just right.

We get some scene stealing by Johnson and Vaughn, a mixture of humor and pathos from Frost and Headey (yeah, Cersei Lannister), and quick glimpses of WWE wrestlers Big Show, Sheamus and John Cena.

There have been plenty of wrestling movies over the years, ranging from the seriousness of “The Wrestler” to the goofiness of “No Holds Barred.” But this one succeeds on a different level. It feels real and it is real.

Ed Symkus writes about movies for More Content Now. He can be reached at esymkus@rcn.com.

“Fighting with My Family”
Written and directed by Stephen Merchant
With Florence Pugh, Jack Lowden, Nick Frost, Lena Headey, Vince Vaughn, Dwayne Johnson
Rated PG-13