'Will you shut up, man?': Joe Biden descends into high school fight mode with Trump in first debate​

Biden called Trump "buddy," said, "this man doesn't know what he's talking about," challenged him to "keep yappin'" — and at one point asked Fox News moderator Chris Wallace and the socially distanced audience, "Folks, do you have any idea what this clown's doing?"

But the former vice president's heaviest hit at that point was pleading with the leader of the free world during one of their nearly countless contentious exchanges, "Will you shut up, man?"

Say it ain't so, Joe

Most folks probably figured Biden would unearth some version of his famous angry pushback that inevitably ends with his hippy-forward suffix ... "man!"

At least one "C'mon, man!" would have done the trick.

But no, Biden pulled out the big guns and let loose: "Will you shut up, man?"

It has to be a first for presidential debating.