The stabbing happened at the intersection of 46th Street and 7th Avenue around 2:00 p.m.
According to police, two men who knew each other got into an argument and escalated into violence.
Police say one man pulled a knife, and the other tried to shield himself with a folding chair, but couldn't block the attack.
The victim was stabbed in the chest.
He was taken to Bellevue hospital in stable condition.
The suspect fled towards 8th Avenue, but police say they did take him into custody.