An off-duty NYPD cop was slashed in the chest while he was mowing the lawn outside his Queens home Thursday afternoon, according to cops and law enforcement sources.

The officer, who works for the department’s Critical Response Command, was approached by an emotionally disturbed man around 3:15 p.m., police and sources said.

The officer asked the alleged perp what he was doing before the suspect pulled a knife and slashed him, sources said.

When officers reached the scene, the victim had a laceration on his chest, police said.

The alleged attacker was taken into custody. No charges have been filed.

The off-duty cop was taken to a local hospital and is in stable condition, police said. 

Additional reporting by Amanda Woods