Three men – two of them senior citizens – were hurt in a nine-hour burst of unprovoked violence in the city’s subway system early Tuesday, cops said.

The mayhem began around 12:25 a.m. when an unhinged man bashed a 32-year-old straphanger in the head with a metal pole on board a northbound A train at the Ozone Park-Lefferts Boulevard in Queens, authorities said. 

The blow left the victim with a visible cut on the left side of his neck, but he refused medical attention at the scene. 

A crazed man struck a 32-year-old straphanger in the head with a metal pole on board a northbound A train at the Ozone Park-Lefferts Boulevard in Queens, police said. WAYNE CARRINGTON

The alleged attacker, Wesley Saint-Vil, 27, was arrested about five minutes later and charged with felony assault, cops said. 

Saint-Vil has nine prior arrests, though all but three of them are sealed, authorities said. 

The most recent bust was for petit larceny in August in Upper Manhattan, police said. 

Before that, Borden – who lives in a Queens housing facility for homeless veterans – allegedly slugged a 61-year-old man who was smoking outside the building in an unprovoked attack, cops said. 

In an unrelated assault just after 6 a.m., a stranger repeatedly punched and kicked a 71-year-old man on the southbound A train platform at 175th Street, police said. 

The beatdown left the senior with multiple cuts on his head and nose, police said. 

A stranger repeatedly punched and kicked a 71-year-old man on the southbound A train platform at 175th Street, cops said. Stefano Giovannini

He was taken to Harlem Hospital, where he was listed in stable condition, cops said. 

The alleged assailant, who had a dark complexion and was last seen wearing a navy blue sweatshirt, gray pants and black backpack, fled on an A train, authorities said. 

The violence continued during the morning rush hour, when a 65-year-old man was punched by a stranger on board a southbound L train at the Third Avenue station in the East Village. 

A stranger slugged a 65-year-old man during a clash over space on a rush-hour train passing through the Third Avenue station in the East Village, cops said. Helayne Seidman

The victim was riding the train when he asked another commuter – who was standing over him – to move back, police said. 

But the stubborn rider refused, before stepping on the seated straphanger’s foot and challenging him to a physical fight, police said. 

When the victim stood up, the brute punched him in the back of the head, leaving him with a large bump, cops said. 

The violence comes amid a slight spike in attacks in the city’s subway system so far this year. Helayne Seidman

The victim got off the train and was treated at the scene by EMS workers, police said. 

The attacker – described as a man in his 30s wearing a gray sweater with a gold chain – stayed on board and has not been caught. 

Assaults within the city’s transit system have slightly spiked so far this year, with 476 attacks reported on the rails through Sunday, according to the latest NYPD data. 

The NYPD tallied a total of 462 assaults within the city’s transit system during the same period last year.