L.A. Clippers player Patrick Beverley fired a basketball at a courtside heckler Sunday night after the fan allegedly said, "F*ck your mother" ... the 2nd major incident between a player and a Mavs fan in 2 weeks.
The 30-year-old guard had reportedly been trading verbal jabs with Don Knobler -- a local celeb in Dallas -- throughout the Clippers' game on Sunday ... when things reached a boiling point in the 4th quarter.
So, what set Beverley off? Don't talk about his mother.
Beverley grabbed the ball and threw it at Knobler -- who calmly collected it after it struck him in the leg.