In Chain of Memories:

-You fight Vexen several times. Once with Riku and twice with Sora. After being weakened by Sora, Axel comes in and finishes the job.

-Riku defeats Lexaeus. As he was dieing, Lexaeus released all the darkness in him out to try to sink Riku in darkness.

-Zexion tries to play a mind trick on Riku. Riku finally sees through it and strikes Zexion, who runs away. (However in Final Mix, they fight) Zexion retreats, but is later absorbed by Riku Replica.

-Sora first defeats a clone that Marluxia made of himself, and later defeats Marluxia himself.

-Sora fights Larxene twice, the second time defeating her.