Police say the 18-year-old victim claimed she was attacked in Crotona Park as she walked home from work.
Eyewitness News has learned that the victim is telling police the suspect came up behind her, pulled her hair, punched her in the face, threw her to the ground and sexually assaulted her.
The woman went to the hospital and reported the assault.
Special Victims Unit detectives responded to the hospital and were interviewing the victim.
The investigation is in its preliminary stages, and no arrests have been made.
The suspect is described as a Hispanic male, 25 to 30 years old, standing 5-foot-8 with a stocky build and wearing dark clothing, jeans and construction boots.
Officers responded to the park, taping off a section while collecting evidence.
Now fearful and planning to be more cautious, women who live around and near Crotona Park are reacting to word of the assault.
"No park in New York City after dusk is safe," said area resident Pat McFarlane. "Her best bet would have been to stay in a well-lit area."
And MacFarlane's daughter Alaina Gandy also takes special precautions when she is coming home late from work.
"I walk in a well-lit area and make sure nobody is around, and then hurry up and go into the building, because you never know what can happen," she said.
"If you live around this area you know not to walk around the park by yourself," said area resident Jeannette Lopez.