A 31-year-old man was slashed in the face during an argument inside a Brooklyn subway station early Wednesday, cops said. 

The victim was arguing with another man inside the Brighton Beach station around 5 a.m. when his rival knifed him, police said. 

He was taken to NYU Langone Hospital—Brooklyn with a non-life-threatening injury. His attacker took off.

Cops had no details on what the dispute was over.