won and defended the title four times. Horn won the bout via unanimous decision, becoming the new King of the Cage Light Heavyweight Champion. Two fights later, Horn fought in the IFC Light Heavyweight tournament on September 6, 2003, and won his first bout of the night via armbar submission before facing future Ultimate Fighter Winner, UFC Light Heavyweight Champion, and UFC Hall of Famer, Forrest Griffin in a highly anticipated bout. The two exchanged powerful strikes on the feet and battled on the ground in the first round, and continued to grapple through the second round until Horn knocked out the fatigued Griffin with a single head kick. Horn's next fight of the night was for the final against future Strikeforce Light Heavyweight Champion Renato "Babalu" Sobral. Sobral was able to overwhelm Horn from the start of the fight with his strikes and grappling skills as he took down Horn who then attempted a triangle choke before Sobral escaped from the position. Later in the round, Horn took down Sobral, who in turn was able to get back on top of Horn and continue to utilize the ground and pound technique while again Horn came very close to executing a successful triangle choke which he held until the end of the round. At the start of the second round, the two exchanged submission attempts until Horn, while ground and pounding Sobral from the top, unintentionally landed an illegal knee strike to the face of the downed Muay Thai fighter. After the fight continued, Sobral took down Horn and the two continued to battle from the ground until the end of the fight. Horn ultimately lost in a unanimous decision in a very entertaining fight. Two fights later, Horn defended his King of the Cage Light Heavyweight Championship title against former King of the Cage Middleweight Champion, who had vacated his title when he moved up to the Light Heavyweight division. Two fights later, Horn fought for TKO Major League MMA against UFC veteran, David Losieau and won via guillotine choke submission under one minute into the first round. Horn then fought against future UFC veteran Chael Sonnen and won via TKO due to a cut 3:34 into the fight. Two fights after the win over Sonnen, Horn fought future longtime UFC Middleweight Champion, Anderson Silva in Seoul, South Korea. Horn was outmatched by Silva's striking and multiple takedown attempts