UFC's Stephen Nguyen Defends Ref Jason Herzog Over Fight Stoppage

Stephen Nguyen is coming to the defense of Jason Herzog after the well-respected MMA ref opted NOT to stop his fight with Mohammad Yahya ... despite his opps face being destroyed during the UFC on ABC event!

TMZ Sports spoke to the 32-year-old, 10-2 fighter just days after the controversial fight -- which resulted in one of the more grusome injuries we've seen -- and while many may believe Herzog dropped the ball, Nguyen isn't one of them.

"To be honest, when I was in the actual fight, I saw his eye, but I almost didn't think anything of it. Like, obviously this guy's still throwing hard at me. Yeah, his eye was messed up, but his hands said different," Nguyen told us.

"The guy was throwing, he was still throwing everything he had at me."

Ultimately, the fight was stopped after the second round (meaning SG won by TKO) ... but it wasn't Herzog who pulled the plug. Instead, it was the Octagon-side physician.

And, Yahya, 31, wasn't happy with the decision.

"Literally right when I got my hand raised, I talked to [Mohammad], he's telling me that he still wanted to keep fighting. And, you know, I have a lot of respect for that," Nguyen explained.

"We don't even know each other, but now we know each other so well, and obviously it's a warrior's code, you know, and I have nothing but respect for anybody that walks in [the Octagon], but especially for him, he fought his heart out."

So, what's next for Nguyen ... fresh off the impressive win? What's he going to buy with the $50k bonus he received??