Jones' toughness stands out in Toronto

All of the questions regarding Jon Jones' chin heading into his 10th, 11th and even tonight's 12th UFC fight were more of a hype-game curiosity.

Surely every man has a vulnerability, and it's easiest to prescribe vulnerabilities toward whatever is left that's unknown.

Against Vitor Belfort at UFC 152 in Toronto, in a fight in which Jones stood as an 8-to-1 favorite and was greeted with a chorus of boos, his chin was never in question. But, for the first time in his still-young career, the light heavyweight champion's mettle was.

Belfort snared Jones' arm in the first round and torqued it back for an armbar. For a long few moments, the Air Canada Centre crowd held its collective breath as Belfort strained to finish the job.

Jones, hearing his right arm pop as it hyperextended, pried with his left hand to release it. It was on tight enough that Jones was faced with that decision that makes most men squeamish -- tap and get it over with or struggle on until it breaks.

He was resolved to keep going and let it break. But before it did, he was fortunate enough to free himself of the threat.

Aside from the Matt Hamill disqualification back in 2009, it was the closest we've seen Jones come to an actual defeat. It was a rare moment of vulnerability, in which he was the one on the ropes. But instead of exposing a weakness with Jones, Belfort might have shed light on yet another strength -- Jones' resolve.

From that point on, it was all the champ. Even with an injured right arm that he nursed noticeably after the fourth-round Americana that put Belfort away (which he fears might be nerve damage to the bicep), Jones controlled the range with leg kicks and jabs.

"It just felt numb, it was just a real numb feeling," Jones said afterward of his right arm. "My brain is trained to throw it, and I just threw it and it definitely didn't feel powerful at all. It was just a real numb feeling, so I'll have to see what's wrong with it."

Jones hurt Belfort in the third round with a wicked kick to the body that dropped him. When the fight went to the ground -- and there were times when Belfort pulled guard throughout -- Jones dropped vicious elbows.

In the end, it was another dominant performance for Jones, who defended his belt for the fourth time and picked up his eighth victory since the Hamill disqualification. Yet, that he faced adversity for the first time in the cage was telling.

Here was Jones, the villain of the past month to many MMA fans who blamed him for the cancelation of UFC 151, displaying the kind of mind-over-matter toughness that only adds to his mystique. Not only did he overcome the trouble, but he outlanded Belfort 65-16 in significant strikes. And he finished the fight anyway.

"[Vitor] got that armbar in every way, shape and form," Jones said. "I've never had my arm pop like that before and, I don't know, I felt it, but I worked too hard to give up. I honestly was waiting for it to break. I was not going to tap out. But man, I tell you what, I've never felt that before."

Now he has. And for all the unknowns that go into Jones the 25-year old champion, it's the things we learn about him each time out that look scariest.

At UFC 152? It was that he doesn't have quit in him, right when quitting was at its most tempting.