The following story contains potential spoilers for the upcoming "Road House" remake.

The return of Jon Jones is the dominant story of UFC 285, but the former light heavyweight champion wasn't the most famous person to enter the Octagon on Saturday.

Between the early prelims and prelims at T-Mobile Arena in Las Vegas, actor Jake Gyllenhaal made an appearance as part of the filming of his upcoming "Road House" remake, which will see the Academy Award nominee play a former UFC fighter.

The movie will apparently see a glimpse of that UFC career, though, as Gyllenhaal faced off with a fellow actor in a fake bout that saw him let his opponent, former UFC fighter Jay Hieron, hit him in the face multiple times before responding with a flying knee and knockout. And then he kept hitting the clearly unconscious fighter, which will probably be how he becomes an ex-UFC fighter.

The proceedings weren't televised, but fans and reporters got the full show:

It might also be worth noting the original "Road House" features a protagonist with a mysterious past that included killing a person, which could be what is supposed to be happening there.

Gyllenhaal fully committed to the part, including his Octagon entrance:

He also provided some more detail into his character on Friday at weigh-ins:

That's not the only way the "Road House" remake will have some MMA flavor, as former UFC champion Conor McGregor is also part of the cast in an unspecified role.