After either the singles or the doubles championship in the Island Open, Alex will arrive at the dormitories and will escort Ace and Clay to the statue next to the training facility. It will open, revealing a secret stairway. On the other side, Alex will introduce the pair to Mario and Toadsworth, who learned of their success in the Island Open and invite them to the Mushroom Kingdom. After accepting the invitation, all four take a private airplane to the Peach Dome, where Princess Peach will greet them and begin The Peach Tournament.
The Peach Tournament is divided into singles and doubles championships. Each match is 5 sets and 2 games long. Defeating the character in either championship will unlock a star version of that character that can be used in exhibition mode. The order in which the player battles the other characters in the tournaments is predetermined for the first time. Unlike the Island Open, the player may repeat the Peach Tournament again without having to create a new file. After completing the tournament once, the characters (and teams for doubles) will be randomized in subsequent competitions.
|Bowser||Lost the semifinal to Clay/Ace.|
|Donkey Kong||Lost round one to Mario.|
|Mario||Runner-up. Lost the final to Clay/Ace.|
|Peach||Lost round one to Clay/Ace.|
|Waluigi||Lost the semifinal to Mario.|
|Clay and Ace||Winners|
|Bowser and Waluigi||Runners-up. Lost the final to Clay and Ace.|
|Donkey Kong and Luigi||Lost round one to Clay and Ace.|
|Mario and Peach||Lost round one to Bowser and Waluigi.|
- Bowser is the only character the player battles in both singles and doubles.
- Luigi does not participate in the singles tournament. However, he may participate after the player completes the singles tournament for the first time.
- Unlike the Island Open, there are no seeded players. The players given the byes are randomized after the first tournament is completed.