Humiliation.
Two examples, in recent memory.
Nogueira getting his arm broken by, then tapping to, Frank Mir - an opponent he hates, and a fellow BJJ practitioner - after never being submitted before.
Vinny Magalhaes being given a 'winnable' fight in Anthony Perosh - a 40yr old BJJ artist with no stand-up to speak of, when Vinny was regarded as perhaps the best BJJ artist in the sport. Vinny goes onto seriously disrespect and disregard Perosh....and gets fucking LEATHERED inside 20seconds, like, sparked out cold by the guy with no striking.