A masturbating man tormented a woman on a Lower Manhattan subway Thursday morning, cops said.

The disgusting chain of events unfolded when the creep approached the 22-year-old victim as she was sitting on a bench on the southbound R line platform at the Cortlandt Street subway station at about 7 a.m., cops said.

The attacker first touched the woman’s thigh and started to masturbate before following her onto the train and ejaculating on the subway car floor, cops said.

The perv then got off at the Court Street stop.

The NYPD released a photo of the suspect Thursday afternoon and asked the public’s help in tracking him down.