A San Diego man was being treated for a brain injury Tuesday suffered when he was punched in the face at a residence in National City.

The victim was attacked by an unknown assailant at a home in the 200 block of A Avenue near East Second Street around 1:45 p.m. Monday, according to a National City Police statement. He was knocked out with one punch to the face.

The victim eventually regained consciousness and drove himself to Scripps Mercy Hospital Chula Vista, and was diagnosed with a brain injury. Police said he was later transferred to UC San Diego Medical Center to receive further treatment.

A description of the assailant was not immediately available.

—City News Service