An NYPD detective who also serves as a paramedic in Eastchester is being hailed a hero for saving the life of a 1-year-old boy.

It was supposed to be a day for Mark Rubins to show support to his 448 fellow men and women in blue for the NYPD graduation at Madison Square Garden. But at one point, all he could hear was, "My baby's not breathing."

A mother's 1-year-old son turned blue and became lifeless after having a seizure while eating a cheese puff.

Rubins found himself back on the job as a paramedic, in the middle of a police graduation ceremony, trying to save another life -- and he did.

"Put the baby over my leg. Delivered a series of chest thrusts, back blows," Rubins says. "I heard like a faint cry, and he kind of looked up at that point, so I picked up and kind of cradled him against my shoulder."

As a paramedic, Rubins spends two days a month working 12-hour days for Eastchester EMS. He says saving a baby's life was a first for him.

Rubins says he doesn't consider himself a hero, but he's glad baby Daniel's father got the chance to graduate from the force and share that moment with his son.