First, play a tournament up to elimination mode or another point at which you want to continuously retry. Then, insert your SD card, copy your saved file onto it, and play the game normally. If you lose, erase your internal Wii saved file, and replace it with the SD card's saved file. This allows you to continue from where you left off until you can win the tournament. The game will not detect you cheating like it does with turning off the power or resetting.

Note: This trick requires a SD card and will erase all of your Mario Strikers Charged WiFi statistics (Mii data can not be stored on a SD card).