Ron Artest III just totally DUNKED on his dad, Metta World Peace ... saying it doesn't bother him if Metta roots for his competition, because he roots for his dad's old rival ... LEBRON JAMES.
Ron III just got the biggest win of his high school basketball career when his Beverly Hills High team beat Crossroads, a squad led by prep phenom Shareef O'Neal.
TMZ Sports talked to Metta about the big win ... who revealed a shocking fact that he was ACTUALLY ROOTING FOR SHAREEF OVER HIS OWN SON!!!
We brought it up to Ron III when he joined the guys on the "TMZ Sports" TV show Thursday, and his response to his pops couldn't have been more priceless, or more savage.
Be sure to catch the full interview on "TMZ Sports" tonight on FS1.