Police say they arrested Luis Chavarin after the fight happened around 4 a.m. Monday at the Loose Caboose on West Flamingo Road.
Chavarin told police he was at the tavern with his friend when he started arguing with another man about the music on the jukebox. Chavarin told officers the man started swearing at him and getting close to him, so he started punching him.
Witnesses told police that when the victim hit the ground and went unconscious, Chavarin tried to help him.
Authorities didn't say whether they think the beating or the fall to the ground caused the man's death.
Chavarin was arrested on suspicion of "open murder," which allows prosecutors to amend the charges once they have more information.