A man was stabbed in the neck during a fight on a Bronx train over the weekend, cops said. 

The 33-year-old victim was arguing with another straphanger on a No. 4 train at the West Burnside Avenue and Jerome Avenue station around 7:30 p.m. Sunday when the assailant suddenly stabbed him in the neck with an unknown object, police said. 

The victim was taken to St. Barnabas Hospital, where he was listed in stable condition, cops said.

The attacker ran off and has not yet been arrested. 

In a separate incident around 4 a.m. Monday, a man was robbed at knifepoint onboard a No. 6 train at East 33rd Street and Park Avenue in Manhattan, authorities said. 

The 21-year-old straphanger was riding the train when a man approached, displayed a knife and snatched his cellphone from his hand, police said. 

The victim was not stabbed or slashed but sustained a cut on his hand when the suspect grabbed the phone, authorities said. 

The victim refused medical attention, and the thief remains at large.