Nguyen was also wounded in the right arm during the 4:35 p.m. shooting at 149 Ridgewood Ave. near Essex Street where the cop and his partner were responding to a 911 call of an emotionally disturbed person.
Police said the shooting began shortly after the woman's call about her son, whom she said was not violent and unarmed.
Police say a revolver and a semi-automatic handgun were found at the suspect's side. She warned them that he may try to run from them, so a second officer went around the back of the home as Nguyen headed to a rear bedroom, where the man was barricaded.
As Nguyen approached the room, the man inside fired, striking the officer once in the arm and twice in his bulletproof vest, police said.
Officer Hart Nguyen, 30, who was shot in the standoff, has been serving the NYPD since July 2015.
"He had a great attitude".
Eric Phillips, spokesman for Mayor Bill de Blasio, said the mayor was on his way to Jamaica Hospital Center. "Thank God our officer is going to come through okay in this case", Mayor Bil lde Blasio told reporters Thursday. He's a courageous young man.
Police rescued the alleged shooter's mother from the house and then surrounded it along with state troopers and K9 units.
The gunman has only been identified as a 29-year-old man.
Two guns and ammunition were recovered in the apartment. The officer's vest abosrbed a shot to the chest, a law enforcement source said.
Officials said Nguyen's bulletproof vest kept him from suffering injuries that could have killed him.
Nguyen of the 75th Precinct has been on the force for just over two years.