Mir KO'd critics and opponents in '08

Some fighters are lucky to have one defining moment in their career. Frank Mir had two in 2008.

Add to that feat the fact Mir was never supposed to walk properly again -- let alone compete in mixed martial arts -- after a horrific motorcycle accident in September 2004 broke his thigh bone in half, and you have Sherdog.com's Comeback Fighter of the Year.

Mir's journey was one of high stakes in a high-stakes sport. A novice entering the Octagon with only two professional bouts to his name in 2001, the 21-year-old Las Vegas native breezed through his first two opponents -- the seasoned Pete Williams and Brazilian jiu-jitsu black belt Roberto Traven -- with what looked like the greatest of ease. By his seventh UFC fight, Mir had lost only once and was vying for the heavyweight title. The sight of Mir snapping Tim Sylvia's arm like a twig in only 50 seconds at UFC 48 haunts many fight fans' minds.

Mir's fall was just as dramatic as his rise. The accident, which occurred when a car hit Mir's motorcycle at 50 miles per hour, threw the fighter more than 100 hundred feet onto nearby pavement. Mir still has his helmet, complete with a piece of cement firmly wedged in it, as a reminder.

It might be cliché to say Mir's road back was a rocky one. Mir struggled in training and battled alcohol and depression. A return at UFC 57 in February 2006 was woefully embarrassing as Brazilian Marcio Cruz pummeled Mir bloody until the referee stopped the bout late in the first round.

A decision victory over Dan Christison five months later was offset by another beating at the hands of Brandon Vera at UFC 65 that November.

And then the win-or-go-home ultimatum came from UFC officials. Three years removed from that life-altering September night, Mir submitted Antoni Hardonk at UFC 74 in a swift 77 seconds.

In February, the former UFC heavyweight champion was assigned the task of defending the sport's honor when he squared off against Octagon newcomer Brock Lesnar at UFC 81. Though an accomplished amateur wrestler, Lesnar had risen to notoriety in the world of pro wrestling and fans and proponents alike weren't about to be shown up by an entertainer. Mir delivered in spades, snagging the hulking Lesnar's leg with a kneebar at 1:30 of the first round.

At UFC 92, Mir joined the company of Fedor Emelianenko, Josh Barnett and Dan Henderson when he iced UFC interim champion Antonio Rodrigo Nogueira in under two rounds. Noguiera had been expected to easily excel in the standup game, but it was Mir who unloaded on the resilient Brazilian and stopped him for the first time ever in his illustrious career.

An elated Mir told interviewer Joe Rogan moments later that he'd never been so afraid to step into the Octagon as he had on that night.

"To come back and fight the best heavyweight to ever fight in the UFC and get a win over him after what I've gone through, it just shows … I'm proof you can do things," Mir said. "I didn't think I could beat Nogueira. If I was a betting man, I wasn't on Mir's side tonight. I came through this with the love of my family, my children, my wife, everybody."

At the postfight news conference, Mir credited the weakest link of his ever-developing game -- his conditioning.

"I'm not afraid to go ahead and showcase my skills," Mir said. "Before, I'd walk into the Octagon terrified of getting tired. I wasn't thinking about the guy I was fighting. I'm thinking, 'Man, if this fight doesn't end in two minutes, I'm in a lot of trouble.' [At UFC 92], I was, like, 'It could go 10 rounds. It doesn't matter. I can be here all night long and I won't lose at any position.'"

Loretta Hunt is a contributor to Sherdog.com.