The Smashing Machine: The Real Reason Mark Kerr Swore at Dwayne Johnson on Sight

So, Dwayne Johnson didn’t just bulk up for The Smashing Machine — he basically vanished into Mark Kerr. It’s not hype; even Kerr himself did a double take and swore at him the first time he saw the full look. The movie hits hard in the ring and harder outside it, and a big part of why it works is the wild, very inside-baseball transformation that made The Rock look like someone else entirely.

Quick hit: what you’re watching

• Title: The Smashing Machine
• Director: Benny Safdie
• Cast: Dwayne Johnson, Emily Blunt, Ryan Bader, Bas Rutten, Oleksandr Usyk
• Runtime: 2h 3m
• Rotten Tomatoes: 79%

The face that isn’t his

Johnson’s physical prep is impressive, sure, but the face is the story. Oscar-winning makeup artist Kazu Hiro built a full Mark Kerr likeness out of 22 separate prosthetic pieces — brows, nose, hairline, even the overall head shape — applied daily in a roughly two-hour session. Hiro also covered Johnson’s tattoos and added subtle swelling to sell the damage Kerr took in fights.

Here’s the gnarly part the movie doesn’t show: this is a fight-heavy, sweat-drenched shoot. Sweat pushes under adhesives. Punches tug at edges. Hiro told Variety that noses can start to peel, glue gets forced out, and it turns into nonstop battlefield maintenance between takes. The only way through it was to keep the build simple, durable, and constantly serviced.

Johnson’s side of the grind

On The Tonight Show, Johnson said the job wasn’t just physical. He packed on a little over 30 pounds of muscle, then layered on an emotional and vocal overhaul — and still had to move like a real MMA heavyweight, not a superhero. It’s the most he’s ever disappeared into a character, period.

Mark Kerr’s first look: wait, what?

Kerr assumed Johnson would mostly be, well, Johnson — maybe a wig, call it a day. Nobody told him about the full prosthetic build. So when he first saw DJ in the makeup chair, he let loose a minute of profanity and basically called him a mirror-image doppelganger. Can’t blame him.

Venice reaction: the screening got personal

Kerr watched the film for the first time at the Venice Film Festival, sitting between Johnson and director Benny Safdie, and it hit like a body shot to the liver. The last stretch got so intense he started tapping his legs and arms just to let the energy out. Johnson and Safdie tried to calm him down; at some point, Kerr ended up holding Safdie’s hand for the final half hour.

"The last scene was gut-wrenching, just the intensity of what was going on. DJ [Johnson] is sitting on my left and patting my leg. Benny's on my right and patting my leg, and I ended up holding his hand for the last half-hour of the movie."

Afterward, Kerr praised how honest and unflinching the film is about his life — the pain, the fame, the mess, the whole thing. He called it both brutal to watch and strangely healing.

Bottom line

This isn’t a vanity makeover; it’s a full-on identity swap engineered by Kazu Hiro and lived-in by Johnson. The result is a movie that plays like a fight film on the surface and a character piece underneath — with a lead performance that’s almost unrecognizable in the best way.

The Smashing Machine is in theaters worldwide. If you’ve seen it, tell me if the transformation fooled you too — or if you caught the seams through all that sweat.