Now that’s how it’s done.

An off-duty NYPD captain arrested a teen-aged punk who had broken into several cars in Gravesend yesterday, authorities said.

Captain Tommy Ng, the second-in-command at the 111th precinct in Queens, saw the 17-year-old messing with a car on Bay 43rd Street near Bath Avenue at 9 p.m.

He quickly cuffed the kid and found out he was responsible for at least two other car break-ins that evening, police said.