Steve Armstrong works as a short order cook on a space station somewhere in the galaxy. Overwhelmed by the volume of orders, he repeatedly fouls up and soon finds himself in a confrontation with an alien patron named Vang. After a fight that wrecks the diner and leaves the alien injured, his friend and co-worker Shorty is fired along with him. It turns out that Vang is an Arena fighter, and her manager Quinn confronts Steve. Amazed that a human could beat one of her best fighters, Quinn offers him a contract, but convinced that humans no longer have a place in the Arena, Steve refuses, intending to make his way back to Earth.
Lacking enough money for a ticket, Shorty tries to raise cash by gambling in an underground casino. The raid by authorities breaks the game and in the confusion, Shorty pockets the money. Caught in the act by crime boss and top Arena fight manager Rogor and his enforcer Weezil, Shorty is held for ransom. Steve promises to pay off the debt, so he reluctantly returns to Quinn and signs a contract with her, using the money to free Shorty. Remarkably Steve wins his first match against an alien named Sloth in an upset. After seeing Steve's potential, Rogor tries to contract Steve as his Arena fighter but learns Steve has already signed with Quinn. Steve continues fighting, determined to prove that a human has what it takes to be champion, and soon becomes a top contender.
Rogor becomes worried that his high position in Arena fighting could be jeopardized if Steve wins the championship, so he enlists his consort Jade to seduce Steve and poison him the night before the championship fight with Rogor's top fighter and reigning champion, an alien cyborg named Horn. But medics are able to counteract the poison minutes before the fight, and Steve appears in the Arena surprising Rogor and Jade. Rogor then resorts to Weezil's plan of hacking into the computer controlling the handicap technology used to ensure fair fights. Weezil's accomplice, Skull, successfully interfaces with the computer located in the catwalk high above the Arena and gains control of the handicap, causing Steve to be severely impaired during the second round of the fight with Horn. Shorty quickly suspects foul play and leaves to investigate, finding Weezil and Skull in the computer room. While fighting off Weezil, Shorty damages part of the computer which in turn causes Skull's head to explode. With the handicap computer offline Steve regains his full abilities and ultimately defeats Horn, becoming the first human champion in 50 years.
