A violent menace repeatedly slashed a 46-year-old straphanger in an unprovoked early-morning attack on a Manhattan subway train Tuesday, cops said.

The victim was riding a southbound No. 2 at West 96th Street and Broadway around 4:30 a.m. when 54-year-old Angel Alvarado allegedly approached him, pulled out a knife and repeatedly slashed him, police said.

NYPD officers busted Alvarado at the scene and charged him with first- and second-degree assault, as well as criminal possession of a weapon, authorities said.

A knife was recovered at the scene.

Alvarado, of Harlem, was last arrested for criminal mischief in August of 2019, cops said.  

Previously, he was busted for petit larceny in June of 2016, according to authorities. 

He was nabbed in connection to four robberies in 1992, and his first arrest was for grand larceny in 1989, cops said. 

The brutal slashing came as the NYPD announced 700 more cops would begin patrolling the rails overnight this week.

It also came after several people were slashed, shoved or beaten in the subway system over the past week.