UFC's Chael Sonnen Rips Anthony Smith's Corner, 'You Have a Towel for a Reason'

Chael Sonnen is BIG MAD at Anthony Smith's coaching staff for not stopping the fight against Glover Teixeira after the 4th round ... telling TMZ Sports, "You have a towel for a reason!"

Sonnen -- who has 49 pro-MMA fights under belt -- couldn't believe Smith's corner let him continue into the 5th round considering he was literally getting his teeth knocked out in the Octagon.

"If you're in the corner, you have a towel for a reason and that's to stop a contest," Sonnen explained.

Sonnen says he respects Smith's toughness -- but the coach needs to act as the "adult in the room" and make the tough decisions in the heat of battle to protect the fighter from himself.

"I've heard the term 'A Rocky Moment' -- man, Rocky was in the movies! Rocky wasn't really getting beat up like that!"

Sonnen said he spoke with Smith at length after the fight -- and Smith explained that he refuses to quit in a fight no matter what.

But, Sonnen says that's MORE of a reason for his corner to make the tough call when it becomes clear he can't win the fight.