Take the true story of an eccentric family of Norwich wrestlers, add Dwayne “The Rock” Johnson as a producer, Stephen Merchant as director and you’ll get the unexpectedly sweet, funny and touching comedy hit Fighting With My Family.

The Bevis family consider wrestling a religion, not a sport. Parents Ricky (Nick Frost) and Julia (Lena Headey) nurture the fighting spirit in their children from a young age. In the comical opening scene, we watch Ricky and Julia correct a choke-hold during a living room scrap between their kids to make it more effective. The Bevis parents wrestle under the monikers “Rowdy Ricky” and “Sweet Saraya” Knight, as well as running a gym training new talent and endlessly promoting their talented offspring. They have big dreams for Saraya (Florence Pugh) and Zak (Jack Lowden), convinced they’re destined for WWE stardom.

The on-screen family dynamic is utterly believable, and the quartet have an easy rapport. Merchant directs with the lightest of touches and he highlights the quirky traits of the Bevis family without sneering or poking fun at their working-class roots. He emphasises their work ethic, dedication and ingenuity instead of their social standing, which is a refreshing change.

When an opportunity to try out for the big time come up, Zak seems most likely to be chosen. He’s hungry for this, he’s worked hard and is about to become a father. With a family to support, the stakes have never been higher. When it’s Saraya who is picked to progress to the training camp in the US, the feeling of utter despair in Zak is palpable. He’s clearly happy for his sister but that joy is tainted by jealousy. When Saraya leaves for her exciting new life, Zak can’t even bring himself to see his sister off at the airport. It’s heartbreaking to watch his dreams being lived out by someone so close to him.

The film may follow a familiar pattern – an underdog story of a plucky youngster slogging their way to glory – but the performances and script elevate the film. Without her family support system, Saraya struggles to find her voice and identity. Rebranded as Paige, she is the pale goth girl among the blonde, tanned beach babes who have come from modelling, not wrestling backgrounds. As a WWE production this was never going to be a gritty exposé, but it also doesn’t come across as a straightforward promotional exercise for the company.

Praise will rightly be heaped on Florence Pugh for her performance, but Jack Lowden is a real stand-out as Zak. His devastation and emotional unravelling are beautifully told and completely relatable. He hits the self-destruct button and the bottle and provokes a brutal but darkly comic fight to the musical overtones of Cliff Richard’s Mistletoe and Wine. You find yourself wanting to simultaneously give him a hug and tell him to stop acting like a spoiled child.

We may know where the story is going – especially if you are familiar with the real events – but it’s not about the ending, it’s how you get there. The story sweeps you along and Merchant has made a film which makes wrestling accessible to outsiders, in the same way Billy Elliot was enjoyable for ballet novices. Dwayne Johnson pops up briefly in the role of a lifetime – himself. It’s easy to mock wrestlers-turned-actors but Johnson had the clout to get this project made and that can only be commended.

There’s a line in the film about wrestling being fixed not fake. Paige’s fate may have been fixed, but Fighting With My Family is anything but fake.