Retired UFC light heavyweight Forrest Griffin may have become a household name by winning the debut season the The Ultimate Fighter in 2005, but he already had a reputation to industry insiders as a tough and talented fighter prior to the epic war with Stephan Bonnar in the TUF Finale.

Perhaps that’s why the UFC contacted him in late 2004 with an invite to appear on its new reality series.

Griffin made his professional mixed martial arts debut on Oct. 27, 2001, against UFC veteran Dan Severn. Severn had won the UFC 5 tournament, “The Ultimate, Ultimate” 1995 tournament, and the UFC Superfight Championship at UFC 9.

Severn had a record of 48-6-4 at the time. Inexperienced and outsized, Griffin took the future UFC Hall of Famer to a decision.

He won his next seven fights, including victories over Jeff Monson and Travis Fulton, before entering the IFC: Global Domination one-night, eight-man light heavyweight tournament in September 2003.

The now legendary tournament featured an abundance of future MMA stars. Participants included Chael Sonnen, Maricio “Shogun” Rua, Renato “Babalu” Sobral, Jeremy Horn, Trevor Prangley and, of course, Forrest Griffin.

Griffin submitted Sonnen by triangle choke in the first round of their fight in the opening round of the tournament, increasing his winning streak to eight in a row.

He was knocked out by eventual finalist Jeremy Horn in the semifinal round in his second fight that night, but the MMA world was well-aware of Griffin’s capabilities. “Babalu” Sobral went on to win the tournament and solidify himself as one of the toughest fighters in the sport's history.

Griffin’s reputation grew following his next fight.

In December 2003, Griffin fought Edson Paredao in Brazil. Paredao threw a kick to the body and as Griffin blocked it, he broke his left arm. Despite the injury, Griffin pressed on. After escaping an arm bar attempt, Griffin knocked Paredao out with a right hand.

Following the fight, Griffin retired from mixed martial arts. He was working as a law enforcement officer in Georgia until he received the invitation to be on The Ultimate Fighter.

At the time, the UFC was heavily in debt. The reality show and a new forged relationship with Spike TV would prove to be its saving grace.

The show consisted of 16 fighters, eight middleweights and eight light heavyweights, living in the same house and competing for a six-figure UFC contract.

Griffin advanced to the light heavyweight finals along with Stephan Bonnar. Their epic back-and-forth battle on the finale would forever link the two and forever change the course of the UFC and MMA.

Millions of viewers tuned in and witnessed a slugfest for the ages. Griffin won the fight by unanimous decision, but both he and Bonnar were awarded UFC contracts. The bout was named the 2005 Light Heavyweight Fight of the Year.

The UFC and MMA were catapulted into the mainstream.

Coming off the show, Griffin won his next two fights in the UFC before facing former titleholder Tito Ortiz at UFC 59 in the first fight of their trilogy.

It was the biggest test of his career to that point and he headed into the match-up as a heavy underdog.

Ortiz put him on his back early and unleashed his patented version of ground and pound, but Griffin survived. He came back, winning the final round, but lost the fight via split decision. Despite the loss, Griffin showed he could hang at the top of the 205-pound division.

He won a rematch with Bonnar at UFC 62 before losing to Keith Jardine by TKO at UFC 66.

After defeating Hector Ramirez at UFC 72, Griffin was lined up against Mauricio “Shogun” Rua.

Rua was the top-ranked light heavyweight in the world. He had recently won the 2005 Pride Middleweight Grand Prix and was coming off a knockout win over Alistair Overeem.

It was Rua’s UFC debut and Griffin was his official welcoming party.

Griffin employed leg kicks and pressured Rua throughout the fight. In the closing moments of the final round, Griffin took Rua’s back, flattened him out and applied a rear naked choke, forcing Rua to tap out.

The win earned him Submission of the Night and was named the 2007 Upset of the Year. It also landed him in a title fight with Quinton “Rampage” Jackson.

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