Officer Walter Warkenthien was promoted to detective at an NYPD ceremony Friday, but it is what he did on his way to the ceremony that had police brass talking.

"Even though he was technically off-duty, Walter did what NYPD cops do," Police Commissioner James O'Neill said at the podium for the promotions ceremony. "He did not hesitate: he literally put on his police hat and he did his job."

Warkenthien was waiting for an Uptown 6 train at 86th Street and Lexington Avenue when a man threatened to kill himself by jumping into the path of an oncoming train.

"I was wearing civilian clothes and the only thing I had was this hat," Warkenthien said, gesturing to his NYPD hat. "So I threw the hat on to get a free hand."

Grabbing the man by his backpack, he dragged him away from the platform and through a security door to safety.

"My thought was, 'Tracks, tracks, tracks. I do not want to go on those tracks,'" Warkenthien said. "So I just grabbed him and we ran through that exit, away from those tracks," said Warkenthien.

Warkenthien says two Good Samaritans helped him restrain the man while he called 911. The man was transported to NewYork-Presbyterian Hospital for an evaluation, as Warkenthien made his way to the 23rd Precinct to get dressed for the promotion ceremony.

"Got the rest of this blue dress uniform here, then came down to 1PP [1 Police Plaza] to start the process of getting promoted," Warkenthien said, in his uniform after he was promoted.

Warkenthien's father Walter, a retired NYPD detective, said when his son called him to tell him of his rescue, it made an important day even more special.

"I was ecstatic. I was very proud on a day that was already going to be a very exciting and proud day turned out 10 times better," said Warkenthien's father.

Warkenthien is one of 146 men and women were promoted to the rank of detective on Friday, including Joseph Ayala, one of the responding officers who shot and killed the gunman who killed Officer Miosotis Familia last summer.

"He charged into the face of danger and displayed the upmost courage and valor," said O'Neill.​

On this day, Detective Walter Warkenthien proved himself worthy, too.