A quick-thinking cop saved the life of a man in downtown Brooklyn, authorities said.

A distraught woman approached Officer Kenia Marte about 1:35 p.m. Jan. 22 while she was driving her sergeant on Schermerhorn and Nevins Street, cops said at a 76th precinct community council meeting yesterday.

When Marte reached the 53-year-old, he couldn’t speak and was convulsing—but had two pills of nitroglycerin in his hand, which is used to treat heart conditions.

“She knew exactly what to do,” said Captain Jeffrey Schiff at the meeting.

Marte placed the medication under the man’s tongue, and began to administer CPR, while her sergeant called for an ambulance, authorities said.

FDNY paramedics responded, and gave him CPR until the patient reached Long Island College Hospital, where he stabilized, cops said.

Marte was recognized at the 76th precinct community council meeting yesterday for her life-saving work, where she was honored as the command’s cop of the month. She has five years on the job.