A black belt in Brazilian Jiu-Jitsu under Carlson Gracie, Vitor Belfort was expected to be a savvy and cautious grappler when he first debuted in the UFC in 1997 at the tender age of 19. Fortunately for him—and unfortunately for his opponents—Belfort proved right away that he had a natural affinity for knockouts. He became the youngest fighter in UFC history to score a victory after flattening Tra Telligman at UFC 12. Two more quick knockout victories would follow in the UFC, prompting fans and promoters to label Befort “The Phenom,” a moniker that would prove both apt and premature all at once. Belfort suffered the first setback of his career at the fists of UFC Hall of Famer Randy Couture, losing by TKO at UFC 15, and while he had his fair share of triumphs in the years that followed—including winning the UFC Light Heavyweight Championship with a controversial TKO (due to a lacerated eyelid) over Couture in 2004—Belfort also suffered disappointing losses to Chuck Liddell, Tito Ortiz, Alistair Overeem, and Dan Henderson both before and after winning the title.

In 2007, after rededicating himself to the sport that built his name, a reinvigorated Belfort put together an impressive winning streak with a knockout of bruiser Terry Martin, a particularly vicious knockout of veteran Matt Lindland, who lay prone on the canvas for a frighteningly extended period following the barrage, and a pinpoint KO combination on former UFC Middleweight Champion Rich Franklin upon his return to the UFC in 2009.

Belfort at his best is a coiled dynamo of accurate, concussive punching power and quickness. His standup prowess has propelled him to countless highlight reel knockout victories, including often-replayed dispatchings of Wanderlei Silva, Marvin Eastman, and Tank Abbot in his earlier days. Vitor Belfort is proof positive that quick-twitch muscles can’t be taught, and that in MMA, as in boxing, speed kills.