A man died after an attacker knocked him to the ground with a blow to the face during a Brooklyn road rage feud earlier this month, cops said Thursday. 

Dexter Alexander, 31, allegedly gave his 56-year-old victim a fatal punch at the corner of Schenectady Avenue and East New York Avenue in Crown Heights at around 11:25 a.m. June 8, police said. 

During the fight, Alexander struck him in the face, causing him to fall to the ground, cops said. 

The victim, who has not been identified pending family notification, was taken to the Kings County Hospital Center, where he was initially listed in stable condition with a head injury. 

But his condition worsened and he died of his injuries Friday, authorities said. 

The city Medical Examiner’s Office ruled his death a homicide, police said. 

Alexander, who lives in the neighborhood, was arrested Monday and charged with assault, cops said.

Further details on the road rage dispute were unknown Thursday morning.