It happened near the Beverly Road Station in Flatbush, on the 2/5 line, around 2 p.m.
Authorities say the victim was sleeping on the train when the suspect stabbed him in the head and arm with what appeared to be a screwdriver. The attacker also stole $300 in cash from him.
The victim suffered a laceration to his head and was rushed to Kings County Hospital.
He was said to be conscious and alert.
The investigation is ongoing, and no arrests have been made.
Anyone with information in regard to this incident is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).
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