Easy Career Wins
Career mode - if you are about to get a 10 count press START then choose to "Throw in the Towel". It will take you back to the main menu and the match will not count (no loss to your name.)
You can also simply turn off "Illegal Blows" in the game settings menu. This lets you low blow your opponent for the entire fight non-stop for an easy KO without any dsiqualification. [by: Guest]
Stay Undefeated:
If you get knocked down during any fight in Career mode and it looks like you're going to get knocked out, just shut off your PS3 before the bell rings.
You can then resume the game and start the match again without a loss. [by: mike]