Knockout Kings Codes -

Regain energy:
Hold L1 + L2 + R1 + R2 when given a choice to hit the heavy or speed bag between fights. Two to eight points of energy will be regained, depending on how long the buttons are held.

Fight as a bear:
Press Right + Square, Right + Triangle, Right + Circle, Right + X at the main menu. A sound will confirm correct code entry. Select any boxer to fight as a bear.

Big head boxers:
Press Left + Circle, Left + Triangle, Left + Square, Left + X at the main menu. A sound will confirm correct code entry. Note: This code may only be enabled on custom created boxers.

Taunt opponent:
Press R1 + R2 + X.

Super fighter:
Create a career mode boxer with the name PSIRULES, fight one match, save the game, then reload that boxer in career mode.

Easy victory:
Begin a bout in career mode and knock your opponent down while simultaneously pressing Start. Choose to lose the fight. If timed correctly, the game will place the loss on your opponent.
To win easily with a created boxer, hit your opponent with R2 + Triangle. Because your boxer throws one punch to the body, one to the head, and one to the kidneys, the ref will not make a call.

Hint: Created boxer with strong uppercut:
Create a right-handed boxer. Make him as tall as desired and have a weight as low as possible. Choose any desired appearance. To use the strong uppercut, press R2 + Down + X.

Hint: Custom Frank Bruno:
Create a career mode boxer with the name FRANK BRUNO. Make his height and weight as large as possible and set his hair to be an afro.