The two of them punch and kick each other and, at one point, the student is put in a headlock.
This all unfolded in the hallways of Lincoln High School.
The video recording by a student shows an English teacher and another student squaring off and fighting as other classmates watch.
According to a law enforcement source, the student was late to class.
The student and the teacher argued. Then they say the teacher was assaulted.
The teacher tried to call security from his classroom. It didn't work. He then went to neighboring classroom and was again confronted in hallway.
"So he pushed him and [the teacher] pushed him back and then the kid just swung on him," student Austin Augustine said.
The teacher suffered a wound in the assault that required stitches.
Police say the student is now charged with assault, but his name has not been released since he's a juvenile.
We showed the video to Mary McCoullum, whose grandson attends Lincoln High School.
"You don't fight your teacher. I come from the old school. We did not fight our teachers. We did what we had to do and we did what we were told to do," McCoullum said.
We are not releasing the teacher's name because he hasn't been formally charged.
Police and the school district continue to investigate.
"Our goal is to get to the bottom of this and make sure it does not happen in the future," Lee Whack of the School District of Philadelphia said.
We reached out to the teacher by email for comment, but have not heard back.
EmoticonEmoticon