BJ Penn vs. Lyoto Machida

A clash of two of the sport's all-time greats, BJ Penn fought then-undefeated Lyoto "The Dragon" Machida at K1 Hero's March 26, 2005 event from the Saitama Super Arena in Saitama, Japan. Machida remained undefeated after a surprisingly competitive three round affair, considering that Penn was fighting a man more than 50 pounds over Penn's natural weight class of 155 lbs. Penn, who himself weighed in at 191 pounds for the bout, was clearly exhausted by the larger Machida by fight's end.

Conditioning played a large part in the decision win for Machida, as did Machida's natural strength, weight and reach advantages. Though many called him crazy for taking the bout, Penn comported himself well throughout and proved that, as he often said, he would fight anyone, anywhere and at any weight, relying on his martial artistry. Penn would later return to the UFC, where he continued to fight bouts in the 170 and 155 weight classes. Machida also joined the Zuffa-owned fight promotion, where he dropped to light heavyweight and obtained a UFC championship of his own.