Giselle's Cubone was sent out to battle Ash her after he got angry at Giselle for her demeaning attitude towards him and challenged her.
Cubone used a 'Bonemerang' attack against Pikachu and Ash exclaimed that it was cheating to use projectile items. Giselle quickly responded by saying that it was legitimate move authorized by the Pokémon League.
Pikachu managed to defeat her Cubone without using any Electric moves. Giselle was very surprised with Pikachu's victory because it wasn't in any textbooks or reference books that she had studied.