Patrick Beverley wasn't the only one acting up after the Clippers got booted from the playoffs on Wednesday ... 'cause several LA fans got into an all-out brawl in the stands!!
The footage is wild -- at least 3 dudes decked out in Clipper gear appear to go after a tall man in a black shirt at Staples Center ... with one of the fans using what looks like a beer can during his attack.
Of course, there's a bit of violent history between both teams' backers -- as we previously reported, Suns and Clippers fans threw haymakers in Phoenix after Game 1 of the Western Conference Finals.