Professional MMA fighter Jack "The Ripper" Popaia is bribed by the powerful Mafia leader, Don Jammy Heat, to take a dive in his fight against Pietro Banditos. Jammy Heat told Jack Heat to fall in the fourth round but Pietro falls before Jack can take the dive. He is chased by Jammy and his crew before Jimmy Olsen, the accountant and bodyguard of Sam "Leatherface" Heat, arrives and helps him escape. Jack later works for the Heat queenpin, Jimmy and Eric "E-Man", a pimp and drug maker-dealer, mostly in causing chaos against the Banditos.
Jammy and his henchmen later storm Montcarlo's celebration, capturing Jack and forcing him to work for the Heat, including Benny, Jammy's right-hand man, and mayoral candidate Rev. Winston "Preacher" Goodman. Jack steals a boat, a seaplane and a helicopter for the Heat, as well as fighting the Hispanic street gang, the Banditoss. After crashing the Banditos' party, however, Jack finds that the HEat have kidnapped Jimmy, and are forcing Jack to hand over her strip club, Fire and Vice, to Jammy in exchange for Jimmy.
Jack helps the Montocarlo's save Jimmy by stealing wire tapping devices from an army base and planting it to pinpoint Jammy and Jimmy's position. He later joins Eric and Rick to raid Jammy's casino, where Jimmy is held. They then escape Jammy's soldiers, but at the cost of Rick sacrificing himself to stop reinforcements.