Capumon King!! The Decisive Battle is the twenty-third episode of the Yu-Gi-Oh! first series anime.
Just before this game begins, Mokuba has an argument with his brother, because he thinks that Mokuba will lose to Yugi. When the battle starts, Mokuba has a set of powerful CapuMon, while Yugi having a bunch of low leveled monsters, revealing the Capumat was fixed to gives them either high or low level monsters.
As the battle continues, Mokuba's monsters charge in on Yugi's, while Yugi keeps skipping his own turn, eventually surrounding them. Using strategy, Yugi eventually manages to get one of his CapuMon to an Evolution Tile, thus making it more powerful, and taking down nearly all of Mokuba's monsters, but loses this monster, and finally manages to pull through by using his final monster to defeat Mokuba's final monster.