Fighting legend Kimbo Slice shows no mercy in the ring.

These two big boys get into a fight.

Kimbo Slice knocked out by Seth Petruzelli in 14 seconds at the EliteXC saturday night fights.

These wannabes think they have what it takes to fight mma style.

Kimbo Slice Punches David Blaine on ABC's "Dive of Death"

The National Geographic Channel goes behind the scenes in todays mixed martial arts.

Bas Rutten kicking car crash dummies. Analyzing ground and pound.

Bas Rutten testing bare knuckle punching, boxing gloves, MMA gloves and kicking.

Analyzing knock out spots, grappling and the sleeper hold.

The National Geographic Channel goes behind the scenes in todays mixed martial arts.

Uncover the science behind Mixed Martial Arts as technology tests the limits of some of the greatest MMA masters.

Kimbo Slice vs. Ray Mercer a very quick fight that is over really fast.

Brock Lesnars MMA Debut against Min Soo Kim

Hot sexy chicks in thongs fight martial arts style.