A 3-year-old boy in the Bronx was recovering Sunday after his mother’s boyfriend punched him in the face, police said.

The boy, who is autistic, was attacked about 10:40 p.m. in his home on University Avenue in the Morris Heights section of the Bronx.

After his mother’s boyfriend fled the scene, the boy was taken to St. Barnabas Hospital, police said.

It was not immediately clear what circumstances had led up to the attack.