An unhinged man attacked another person with a knife inside a Bronx apartment Sunday morning — and was shot and wounded by an NYPD officer.

A 911 caller reported that a knife-wielding man was assaulting someone at a building on Grand Concourse near East Kingsbridge Road around 10 a.m., according to cops. 

Officers responded and at least one of them shot the man, cops said.

He was in stable condition and expected to recover.

The relationship between the two people in the apartment was unclear.