Hold or repeatedly tap Left at the game mode selection screen until the sound of a bell is heard.
Avoiding knockouts
In order to avoid a knockout, when your opponent gets close to you perform a grab. You will then exit knockout mode.
Better Ring Performance
Pimp out your ring entrances. The more extravagant they are, the more the crowd will like you and the better you will perform.
Clubber Lang created boxer from Rocky 3
First Name: Clubber
Last Name: Lang
City: Chicago
Height: 6'7"
Stance: Orthodox
Face Shape: Default
Gloves: Pro 1
Trunks: Anything light blue or black
Shoes: Custom blue with feathers
Hair: Mohawk (black)
Facial Hair: Full scruff (black)
Skin: Dark
Extra Fight Store Items
Although you can turn pro at any time, winning an Amateur title belt will unlock equipment you cannot find elsewhere.
Faster first round knockouts
Go to the "My Corner" screen, then go to options. Turn on the 3 knock out rule. Knock your opponent down three times in the first round. Try to do this as fast as possible and beat 59 seconds. You should now have the fastest KO record.
Start a new career and go pro immediately. Go to the settings and turn on 3 knockdown (T.K.O.). Fight the rank 49 boxer and constantly Haymaker him. If he starts blocking, do a Haymaker on the other side. Once you are in Knockdown mode you will need one more Haymaker to knock him down. Once he gets back up it will take about four Haymakers to knock him down again. Try to knock him out in 59 seconds to get the fastest knock out record.
Ghetto Fabulous
Enter Getfab as the first name of a created boxer. Save the created boxer and Ghetto Fabulous will be unlocked under the heavyweights roster.
Knockdowns
As you progress in just about any weight class, you will notice that some of your top opponents always seem to know where you are going to punch when they are dizzy; therefore blocking your punches and preventing a knockdown. To knock down an opponent who uses this type of defense, wind up your Haymaker and rapidly press L about five or six times. Eventually let the Haymaker go, and you will almost always hit your opponent and knock him down.
Li'l Jon
Enter Liljon as the first name of a created boxer. Save the created boxer and Li'l Jon will be unlocked under the light heavyweight roster.
Little Mac
Enter Macman as the first name of a created boxer. Save the created boxer and Little Mac from the Punch Out!!! games will be unlocked.
Small Fighters
Hold Up at the venue selection screen until the sound of a bell is heard. Select a venue to begin a fight with both fighters small.