Investigators say the pair had stepped outside the Yarmouth restaurant Saturday night after arguing inside. Police say the juvenile then punched his 63-year-old father in the face.
The father hit his head on the ground, suffering serious injuries. Police say an off-duty firefighter who was at the restaurant quickly responded and helped save the man's life.
The juvenile was arrested and released later that night into his mother's custody. He is charged with felony assault and battery.