One of the best prospects in the Pittsburgh Pirates' farm system was so pissed off over being hit by a baseball Saturday -- he straight-up charged the mound and attacked the pitcher who threw it.
The wild scene all went down in an Arizona Fall League game in Scottsdale ... when Bucs outfield prospect Canaan Smith-Njigba was drilled in the upper shoulder area by a pitch from Red Sox prospect Josh Winckowski.
In video of the play, captured by Baseball America, you can see Smith-Njigba immediately ran at Winckowski after being plunked -- and started throwing punches.