The woman slashed on a Manhattan subway — in a harrowing attack that also left a good Samaritan injured — had just rejected the suspect’s advances before he pounced on her while shouting anti-Muslim slurs, police said Wednesday.

The knife-wielding brute, who remains on the loose, apparently got enraged when the woman ignored him on an Eighth Ave.-bound L train at about 10:30 p.m. Tuesday, cops said.

He then slashed her in the face, in what police said could be classified as a hate crime.

A 29-year-old bystander came to the woman’s aid — prompting the attacker to turn on him and slash him in the head multiple times, police said.

Both the man and woman were taken to Bellevue Hospital in stable condition.

The suspect fled the Union Square station, police said, leaving behind a gruesome bloody scene on the platform. He has not been identified.

Police did not divulge details of the anti-Muslim slur, but said the NYPD Hate Crimes Task Force has been notified about the incident.

The attack came less than a half-hour after another straphanger was stabbed on a Manhattan train while defending himself from a would-be robber.

The 34-year-old man had been riding a southbound F train near the 34th Street-Herald Square station when a stranger approached, asked for a cigarette and then tried to rob him, authorities said.

As the two men fought, the suspect pulled out a knife and stabbed the victim twice in the stomach. When the train pulled into the station, the tussle spilled onto the platform, where the attacker stabbed the man again before taking off, authorities said.

The victim was taken to Bellevue Hospital with non-life-threatening injuries, cops said.

The back-to-back attacks mark just the latest in the months-long uptick in New York City transit violence that has prompted officials to deploy more cops underground.