Raymond Frolander was sentenced Thursday after he pleaded no contest to lewd and lascivious molestation of a child.
The victim's father told police that he walked in on Frolander abusing his son in July 2014 and attacked him.
When officers arrived to the scene, they found Frolander lying on the living room floor with knots on his face and he was bleeding from his mouth.
No charges were filed against the father.
The identities of child abuse victims and their relatives are not revealed to protect the family.