A man in his 30s was beaten to death during a fight inside a Brooklyn basement early Wednesday, cops said. 

The violent clash broke out inside the building on Fifth Avenue near 48th Street in Sunset Park around 5:30 a.m., authorities said. 

The two men were drinking in the basement when they got into an argument, police sources said. A man who was in his 30s was knocked unconscious by the other.

The unidentified victim was rushed to NYU Langone Hospital–Brooklyn, where he succumbed to his injuries about a half-hour later. 

A male person of interest was taken into custody, cops said. No charges were immediately filed. 

The two men knew each other, cops said.