It happened outside of 1 Centre Street just after 11:30 a.m.
The victim is a Brooklyn resident who was waiting to go to court to answers a summons.
He told detectives he was talking to a woman in line when the suspect came up behind him and slashed him.
The suspect stabbed him in the lower neck and upper back and fled toward Centre Street.
The victim was taken to the hospital where he is expected to survive.
He told police he did not recognize the suspect.
The suspect was wearing a dark leather jacket and brown hat and ran toward Reade Street.
So far no arrests have been made and the investigation is ongoing.
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