MTA worker Anthony Mannino went from signal maintainer to hero on Wednesday — jumping onto a live track to stop a train from hitting a woman in Brooklyn, sources said.

Mannino was on a job near the Newkirk Plaza Q station around 10:30 a.m. when he saw straphangers yelling about a person being on the tracks — just as a train was pulling in, according to an MTA source.

“I was on the south end of the southbound platform and I just heard people screaming,” Mannino told The Post. “I look over — I see a lady — late 40s – in the middle of the roadbed…I’m thinking there’s no way the motorman is going to see this lady where she was, especially with that curve coming into the station.”

There was not enough time to put the woman onto the platform, according to Mannino, so he knew he had to get the operator’s attention.

“I said, I have to get out there,'” recalled the 54-year-old. “I jumped onto the tracks and flagged the motorman to stop the train…about 3 feet away from hitting her.”

Mannino said he pulled the woman — who voluntarily jumped onto the tracks — aside afterward and explained the seriousness of her actions.

“I said: ‘Listen, you almost killed yourself. We gotta get you off the tracks. There’s no way something’s going to happen to you today…Nothing’s going to happen to you on my watch. Not today.’ ”

Motorman Larry Moreno said he was going about 35 mph when he spotted Mannino.

“When I’m coming into the station. I cannot see into the station until I come around that curve,” he explained. “As I’m coming in to the station…I see signal maintenance worker coming into the path of the train. I knew something was wrong.”

Moreno put the train “into emergency,” and Mannino escorted the woman to safety. Then, just as quick as she came into his life, the individual was gone.

“I walked her out, I pleaded with her [but] she did not want to go to the hospital,” Mannino said. “I was hoping I could flag a cop. I walked her almost a block and a half three blocks away — and she just took off.”

NYC Transit president Andy Buford praised the two men for their actions.

“This is another example of the caliber, bravery and passion of New York City Transit front-line workers,” Buford told The Post. “Anthony and Larry did a great job under incredibly stressful circumstances and I am immensely proud of them.”