Sebastiaan "Bas" Rutten (Dutch pronunciation: [ˈbɑs ˈrʏtə(n)]; born February 24, 1965) is a Dutch retired mixed martial artist (MMA), Karate and Taekwondo blackbelt, and Muay Thai kickboxer. He was a UFC Heavyweight Champion, a three-time King of Pancrase world champion, and finished his career on a 22 fight unbeaten streak (21 wins, 1 draw). Fight Matrix lists Rutten as the third MMA heavyweight lineal champion with the second longest reign in MMA history.