Police say 27-year-old Michael Barriga was at his father Augustine's home in Avenal last Wednesday when the two got into a fight.
Authorities say Michael punched his father, causing him to fall back and hit his head on a wall. The 51-year-old was taken to Community Regional Medical Center where he died Sunday afternoon.
Michael was arrested Friday for felony assault, but those charges have now been upgraded to murder since Augustine's death.
This is the first homicide for Avenal police this year.