Castillo become of good form the Campeonato Carioca, saving a penalty to Victor Hugo of Friburguense in the 4–1 win of Botafogo, in the first official game of "The wall" for that tournament. Due to his good performances for the Carioca against Flamengo and Fluminense, the biggest rivals of Botafogo, he came to be idolized by the club's fans. In April 2008, he won the Taça Rio, after a 1–0 victory over Fluminense with a goal of Renato Silva in the 84th minute, being this his first title in an international league. However, after the success of Botafogo, his club was eliminated of the Copa do Brasil by Corinthians and the Uruguayan keeper lost his reputation among the fans of the club, due to mistakes that he committed in the second game of the semifinals key. After of this bad moment of the player, was relegated as second choice goalkeeper of Botafogo, being the first keeper Renan, who was contesting the post with Castillo weeks ago.