Raja Jackson Arrested For Brutal Wrestling Ring Beatdown

Raja Jackson attack Kick

Raja Jackson -- the son of UFC legend Quinton "Rampage" Jackson -- was arrested on Thursday for brutally beating down a wrestler at an event late last month.

TMZ Sports has learned the 25-year-old was taken into custody early in the morning ... and booked on a felony charge.

Jail records show he's currently still behind bars ... being held on a $50,000 bond.

The arrest, of course, stems from that ugly incident at a Knokx Pro Wrestling event in L.A., where Raja slammed Syko Stu (aka Stuart Smith) to the mat, and then pummeled him with nearly two dozen punches as he was unconscious.

Mercifully, after 10-11 seconds of repeated blows, other wrestlers stepped in, and pulled…