Lorenzo Lamas' son, AJ Lamas, was arrested for DUI last Friday morning in L.A. -- and get this ... he already pled "guilty."
Law enforcement sources tell TMZ, Lamas -- who starred in a reality TV show about his family called "Leave It to Lamas" -- copped to one count of DUI, driving with a blood alcohol level of .08 or higher, immediately following his arrest. The details surrounding the arrest are unclear.
Lamas was sentenced to 36 months probation and roughly $1,600 in fines.
Lamas was also ordered not to possess any deadly weapons.
He was released from custody shortly afterward. Calls to his reps were not returned.