A man rescued an FIT student as she was being assaulted by a violent sexual predator in East Harlem early Tuesday morning. Police say that the victim, a 19-year-old woman, was exiting a cab at around 4:30 a.m. on Madison Avenue when the male suspect grabbed her from behind, threw her between two parked cars, and "repeatedly slammed her head into ice and snow."

The witness, who the Post identifies as 46-year-old Dale Green, was watching the Olympics when he heard the victim shouting outside and called 911.

“I kept hearing, ‘Please no! God no! F-ing no! Don’t do this! Don’t do this!” ' Green says. He then opened his window to speak with the victim, asking, "Are you OK?" She responded: "No! He's trying to rape me!"

“I can’t believe somebody tried to rape somebody in that spot," Green said. "It’s right out in the open."

Green gave the 911 operator a detailed description of the suspect, then ran outside to confront him. The suspect fled and was stopped by police minutes later.

Demetrius Edwards, 34, is charged with attempted rape. Edwards has three prior felony convictions for rape and sexual assault, and served three years in prison. His file also indicates that he used a firearm against one of his victims, and choked another.