Police arrested a man Saturday night who they say punched a woman in the face after an argument over a subway seat in Brooklyn on Thursday.

Investigators said Derek Smith, 56, seen here, has been charged with assault.

Officials said Smith, seen above, got into a heated argument with a 37-year-old woman over a seat on an N train in Bensonhurst around 7:40 a.m. Thursday.

The city police department said the Brooklyn resident started cursing at the woman and then punched her in the face, cutting her lip.

Smith ran off at the 18th Ave. Station after a bystander stepped in, police said.