Cops have arrested the serial subway saboteur following a violent attack on a woman who was shoved headfirst into a train in Brooklyn on Wednesday, a police source told The Post.

Cops believe Isaiah Thompson, best known for creating more than 700 subway delays this year by pulling the emergency brake, is the brute who randomly shoved the woman into an idling train at the Dekalb Avenue B/Q station in Fort Greene, the source said.

He was taken into custody on Thursday afternoon and charges are pending, the source said.

Shocking video of the incident emerged Wednesday evening — showing a man, believed to be Thompson, jumping and screaming “What!” to frightened commuters around 7:20 p.m.

The man appears to shove someone else before turning his rage onto the female victim who was standing near him.

He pushed the unsuspecting woman with both hands, forcing her to collide face-first into the train.