TMZ Sports has obtained footage of Washington Redskins safety Montae Nicholson pummeling a man in the middle of a Virginia street around 2 AM Tuesday morning ... and it's violent.
Nicholson -- wearing a red hoodie -- is going after another man in a jean jacket while other people in the melee desperately try to restrain him.
But, Nicholson is too strong and too angry -- and refused to back out ... instead, he throws several punches at his target ... including a knockout blow.
You can see in the video, the man in the jean jacket appears to go limp as Nicholson hits him clean in the face.