A 26-year-old man was stabbed in the neck while riding the subway early Friday in Lower Manhattan, police said.

Cops said the stabbing started as an argument between two men on the northbound F train around 1:30 am. before the dispute turned physical and one of the men pulled a sharp unknown object.

The attacker — who was described as a man in his mid-20s with a pony-tail, wearing blue jeans — ran once the subway car arrived at the Broadway-Lafayette Street station, according to cops.

The victim was taken to Mount Sinai Beth Israel where he was expected to survive, according to authorities.