UFC Hall Of Fame Fighter Stephan Bonnar Dead At 45

It was a back-and-forth bloody battle between two finalists. An exhausted Forrest Griffin gets his hand raised after a unanimous decision victory over a then 28-year-old Stephan Bonnar in the Light Heavyweight finals of the inaugural season of "The Ultimate Fighter" reality show on April 9, 2005.

The fight was so good, not only did the winner Griffin secure a long-term deal with the fight promotion, both fighters received six-figure UFC contracts. Their future's in the sport of Mixed Martials Arts were just getting started.

Bonnar, UFC Hall of Famer and professional wrestler who helped launch the UFC into the mainstream with his fight against Forrest Griffin, died at age 45, the UFC announced Saturday.

The Hammond, Indiana native died of presumed heart complications while at work, according to the UFC.

"Stephan Bonnar was one of the most important fighters to ever compete in the Octagon," explained Ultimate Fighting Championship President Dana White, via UFC.com. "His fight with Forrest Griffin changed the sport forever, and he will never be forgotten. The fans loved him, they related to him and he always gave them his best. He will be missed."

Bonnar and Griffin were both inducted into the UFC Hall of Fame in 2013. Their legendary bout is regarded as one of the most important fights in the history of the fight promotion. It was voted the greatest fight in UFC history in 2009, before earning a place in the UFC Hall of Fame's fight wing. "The Ultimate Fighter" reality series and that fight in particular were critical to landing and keeping the UFC on Spike cable television network, according to ESPN.

In addition to Griffin, Bonnar went toe-to-toe against world champions Lyoto Machida, Tito Ortiz, Mark Coleman, Jon 'Bones' Jones, and Rashad Evans throughout his career.

At UFC 153 Bonnar faced his toughest challenge in the Light Heavyweight division to date, Anderson 'The Spider' Silva. In front of a packed house at Jeunesse Arena, in Rio De Janeiro, Brazil Silva won by technical knockout 4 minutes and 40 seconds into the first round of the main event on October 13, 2012. It was the last time Bonnar, nicknamed 'The American Psycho' competed in the UFC.

His last MMA fight was at Bellator 131 at Pechanga Arena, in San Diego, CA. Bonnar dropped to 15-9 after the split decision loss to Tito Ortiz on November 14, 2014. At the time it was the most watched Bellator event in its history, according to ESPN.

After his retirement from MMA, Bonnar did color commentary over the years for the World Extreme Cagefighting (WEC) promotion and worked several times as an MMA analyst for ESPN and Fox Sports.

Following his MMA career, Bonnar made his Impact Wrestling debut on November 5, 2017.

"We lost a real legend," UFC commentator Joe Rogan wrote in an Instagram post. Rogan added, "RIP to one of the most important figures in the explosion of MMA. You will not be forgotten."