Mark Kerr was a mixed martial arts newcomer in 1997, but already had the look of a superstar. After watching Kerr maul three opponents in one night, Brazil’s Tatame magazine gave him an appropriately fearsome title: “Máquina de Bater,” or The Smashing Machine.
The nickname stuck, but the pressure to win made Kerr’s dominance difficult to maintain.
The former UFC heavyweight champion’s trials in and out of the cage are the subject of biopic The Smashing Machine, premiering Friday, October 3. Starring Dwayne Johnson as Kerr, the film focuses on the fighter’s early rise through the MMA ranks in the late 1990s and its toll on his personal life.
While Kerr’s winning ways initially grabbed the attention of fans, they masked a substance use disorder the fighter has battled throughout his life.
Kerr was an NCAA wrestling champion
Kerr, born in Toledo, Ohio, on December 21, 1968, is part of a family legacy in combat sports. His father, Thomas Kerr, was a former U.S. amateur boxing champion, according to his obituary.
When Mark was 12, his parents sent him to live in Davenport, Iowa, with his brother Michael, the eldest of the seven siblings. During this time, Mark competed in multiple sports, including wrestling, and developed his imposing physical stature. “When I showed back up to school in Toledo no one knew who I was,” Kerr told Sports Illustrated in 2015. “I changed so dramatically. I went away this puny little punk kid and came back a relatively mature kid who had grown into this man’s body.”
Back in Ohio, Kerr won the 1986 state wrestling championship at 175 pounds his junior year. His success helped him earn a scholarship to Syracuse University, where he became the Division I collegiate champion in 1992—beating another future MMA superstar, Randy Couture of Oklahoma State, in the 190-pound final.
Kerr continued to wrestle with an eye on qualifying for the freestyle bracket in the 1996 Olympics in Atlanta. He trained with Olympic rival Kurt Angle at the infamous Foxcatcher ranch in Pennsylvania, where founder John du Pont shot and killed star U.S. wrestler Dave Schultz in January 1996.
Kerr ultimately lost out on an Olympic team spot to Angle, who won the gold medal at the Atlanta Games and later became a WWE champion and Hall of Famer. He also experienced a devastating personal loss, as his mother Mary died of cancer in September 1996.
Kerr transitioned to MMA to make more money
Unable to reach the pinnacle of wrestling and seeking more lucrative opportunities, Kerr turned his eye to mixed martial arts (MMA) in 1997.
Unlike recent years when competitors such as Ronda Rousey and Conor McGregor became household names, MMA had a barbaric reputation. Its top U.S. promotion, the Ultimate Fighting Championship (UFC), was previously banned in 36 states and underwent rule changes banning brutal tactics such as grabbing and twisting fingers, groin strikes, and headbutts.
Kerr, known for his striking and grappling, embraced the brutality required and made $20,000 for his night in Brazil that cemented his Smashing Machine status. He earned more visibility in UFC, defeating Dan Bobish and Dwayne Cason in a pair of 1997 title bouts.
“He was a brick,” Kerr’s former trainer Bas Rutten told SI, singling out the fighter’s massive forearms. “The same as a piece of stone. For real. Every time I would say, feel, for fun. It’s the craziest thing you’ve ever felt.”
Even more money was up for grabs in PRIDE Fighting Championships, another MMA promotion based in Japan. Kerr built an 8-0 pro record and estimates he made $1.8 million from his fights in PRIDE.
Kerr built a lavish lifestyle and also began a relationship with girlfriend Dawn Staples (played in The Smashing Machine by Emily Blunt). But while everything looked promising in his career, a darker truth lay underneath.
Kerr began using drugs in college and became addicted to painkillers
Around age 20, Kerr was was forced to take a year away from school at Syracuse after being arrested and charged with stealing from another student. He temporarily lost his athletic scholarship and picked up jobs as a stadium concert worker before eventually returning to campus. It was around this time he began experimenting with cocaine and narcotics.
As his MMA career materialized—Kerr insists he didn’t use performance-enhancing drugs while wrestling—he began using steroids and became increasingly reliant on painkillers to combat the physical toll on his body. “The genesis of all this for me starts back when I was fighting and just the amount of pressure I was putting on myself to perform and, you know, not to seek healthy ways to do rehab for my body,” Kerr said. “Wanting the instant relief of a sore shoulder. Take a couple Vicodin, I can train later on that day. Take a couple Vicodin, I can go to the gym later on.”
Kerr’s drug and alcohol use reached a breaking point in 1999, when he experienced an overdose and went to rehab. His relationship with Staples was highly volatile around this time. The pair temporarily separated and, according to Time, had an argument that required police intervention because Staples attempted to harm herself with razors. Kerr and Staples reconciled and married in 2000, but separated for good around 2006. They have one son, Bryce.
Kerr returned to competition, but won only two of his nine fights over the next decade. His last professional match was August 28, 2009—a loss to Muhammad Lawal via knockout in an M-1 Global bout.
Despite Kerr’s exit from MMA, his substance use disorder lingered. He relapsed in 2011 and, around December 2013, entered treatment once again. According to SI, he spent seven months at a halfway house and temporarily experienced homelessness when he could no longer afford his rent.
Kerr recently told Time he is now seven years sober. “I recovered from a seemingly hopeless state of body and mind. It took my son saying, ‘Dad, do you think you can stop drinking?’” he explained.
Kerr is now considered a mixed martial arts pioneer
Thinking about life away from the octagon, Kerr acquired an Arizona real estate license in 2008 and tried working as a personal trainer. He ultimately became a car salesman at a friend’s suggestion and worked at multiple dealerships.
Although his fighting days are long behind him, Kerr is still a celebrated figure in MMA. In June 2025, Kerr joined the UFC Hall of Fame as part of the promotion’s Pioneer Era Wing. This group includes fighters who turned professional before November 17, 2000, when unified rules were adopted across mixed martial arts. The Smashing Machine star Johnson introduced Kerr at the induction ceremony and presented him with a commemorative gold trophy.
During his acceptance speech, Kerr reflected on his addiction and expressed hope his turnaround will serve as a lesson for others battling the disease.
“My purpose is to help someone out there who feels like they can’t make it one more second, or one more minute, or one more hour. I’m here to tell them what a difference one minute makes,” Kerr said.
See The Smashing Machine starting October 3
Johnson’s agent contacted Kerr about acquiring his life rights in 2019. The movie project was announced that year, but delayed due to the COVID-19 pandemic.
After four years, Johnson called Kerr personally to discuss ideas for his portrayal. “It wasn’t transactional, it was heartfelt, like, ‘I’m ready to do this. I’m ready to take on something that’s completely different from what I’ve ever done,’” Kerr said of the conversation.
Kerr served as an informal consultant for writer and director Benny Safdie’s script and worked directly with Johnson and the stunt team during “fight week,” ensuring fight scenes looked as authentic as possible.
Kerr will finally see the project make it to the screen this week, when The Smashing Machine arrives in theaters on Friday, October 3.
Tyler Piccotti joined the Biography.com staff as an Associate News Editor and is now the News and Culture Editor. He previously worked as a reporter and copy editor for a daily newspaper recognized by the Associated Press Sports Editors. In his current role, he shares the true stories behind your favorite movies and TV shows and profiles rising musicians, actors, and athletes. When he's not working, you can find him at the nearest amusement park or movie theater and cheering on his favorite teams.
