Sean Keith Sherk is a retired American mixed martial artist and former UFC Lightweight Champion. Sherk competed in the Ultimate Fighting Championship and was one of the first combatants to have been a championship competitor in multiple weight divisions. He was the second UFC Lightweight Champion in the organization's history after Jens Pulver vacated his title five years earlier. Sherk also spent time competing in the Japan-based organizations, PRIDE Fighting Championships and Pancrase; going undefeated in both promotions. He holds one of the longest undefeated streaks in mixed martial arts history, with only four career losses, all to fellow-UFC Champions. Sherk announced his official retirement from mixed martial arts competition in September 2013 having last fought three years prior.

Jens Johnnie Pulver is an American retired professional mixed martial artist and undefeated boxer and kickboxer. Pulver was the inaugural UFC Lightweight Champion in addition to serving as the head coach on The Ultimate Fighter 5 reality show against long-time rival B.J. Penn. In mixed martial arts, Pulver competed at the Lightweight, Featherweight, Bantamweight and Flyweight divisions in addition to competing at the Middleweight, Light Middleweight, and Welterweight divisions as a professional boxer. While perhaps best known for competing in the UFC, Pulver has also competed in Pride Fighting Championships, for the PRIDE 2005 Lightweight Grand Prix. He is to-date the youngest UFC Lightweight Champion in the UFC history, eventually relinquishing his title, after two defenses, due to a contract dispute. Pulver officially retired from combat sports in 2014.