The woman, apparently in fear of her life, used deadly force, when she was confronted by a group of men threatening her.
Eyewitness News is told there were some unwanted sexual advances made by these men.
The woman reportedly tried to get away from the men and get on the F train, but the men pulled her off the train.
The harassment apparently continued, so she grabbed a knife, stabbed one of the men and then took off running.
Police say this time she made it onto a train and was able to escape.
The man who she stabbed was pronounced dead at the hospital. He was identified as 29-year-old Thomas Winston, who lived in a nearby shelter.
