The MMA world has taken a hit.
UFC Hall of Famer Stephan Bonnar died Dec. 22 at age 45. According to the organization, his cause of death is from presumed heart complications while he was at work. Bonnar is survived by his wife Andrea Brown and their son Griffin Brandon.
"Stephan Bonnar was one of the most important fighters to ever compete in the Octagon," UFC President Dana White said in a statement Dec. 24. "His fight with Forrest Griffin changed the sport forever, and he will never be forgotten. The fans loved him, related to him and he always gave them his best. He will be missed."
Those fans fell in love with Bonnar back in 2005 during the first season of The Ultimate Fighter. His face-off against Griffin in the season one finale quickly became known as one of the greatest fights of all time—and helped launch UFC into the mainstream.
"I didn't think I'd have a UFC career," Bonnar had said. "It was just a little hobby I was doing, so it changed everything. Almost overnight, I became like a celebrity. Everywhere I went, someone would recognize me, even in obscure places...It was wild."
Throughout his illustrious career, Bonnar, who had a 15-9 record, faced off against the likes of James Irvin, Keith Jardine, Krzysztof Soszynski, Igor Pokrajac, Jon Jones, Rashad Evans, Mark Coleman, Anderson Silva, Tito Ortiz and more.
His last UFC fight was in 2012 and he was inducted into the Hall of Fame the following year.
"If you knew @StephanBonnar it was impossible not to love him," commentator Mike Goldberg tweeted after Bonnar's death, "a loyal friend with a great sense of humor who once took over an entire floor of our hotel in Australia preparing his own kangaroo meal! RIP American Psycho, gone way too young!"