A parolee allegedly dragged a woman into the bushes in Prospect Park and tried to sexually assault the 33-year-old — but she fought him off and he was soon arrested thanks to a witness who followed him and called 911, the Post has learned.

The woman was walking in the Brooklyn park just before 6 p.m. when the 25-year-old man grabbed her by her hair and pulled her to the ground, police sources said.

The man then pulled down the woman’s mask and tried to assault her — but she bit his finger and escaped, sources said.

A good Samaritan heard the the woman’s screams, saw the man run off and followed him into a building on Sullivan Place while on the phone with 911, according to sources.

Police quickly caught up with the man, who cops identified as Carlis Clarke, after finding video surveillance of him leaving the building. He was charged with criminal sexual act, robbery, and unlawful imprisonment, according to the NYPD.

Police Commissioner Dermot Shea praised the NYPD’s Special Victim Unit for tracking down Clarke.

“When a woman was sexually assaulted in Brooklyn yesterday, @NYPDSVU went to work, ” Shea tweeted. “Within hours, investigators ID’d & arrested the assailant. No stranger to the criminal justice system, he had just been released on parole.”

Clarke was cut loose on parole on Feb. 11 after serving 16 months in prison on a two-year sentence for a weapons conviction, prison records show.