Hollywood actor Jake Gyllenhaal showed up at UFC 285 on Friday in Las Vegas, Nevada.
Scenes for the remake of the 1989 film Road House were being shot when Gyllenhaal participated in a weigh-in with his co-star, the former Ultimate Fighting Championship (UFC) fighter Jay Hieron.
Gyllenhaal may be seen in viral video getting onto the scales, flexing his massive guns, and yelling at the crowd.
Then, as per the film's script, he got into a fight with his antagonist Hieron and slapped him onstage.
Due to his role as a boxer in the 2015 film "Southpaw," Gyllenhaal is no stranger to intense physical preparation.
According to sports betting picks experts, the film also features Conor McGregor, a former UFC champion. He was there for the weigh-in and helped get the audience amped up for Gyllenhaal.
The main event of UFC 285 is Jon Jones vs. Ciryl Gane, which will begin at about 1 a.m. ET.