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. Play video content

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. Monique C. Martin

Mercifully, after 10-11 seconds of repeated blows, other wrestlers stepped in, and pulled Raja off Smith.

The wrestler -- who had gotten into a sp

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