In June of 1507, after Masamoto was killed by Motonaga KOZAI and Nagatada YAKUSHIJI, the chief retainers of individuals who supported Sumiyuki, Sumimoto organized an army with the intention of attacking Sumiyuki in August of that year, which Takakuni joined, making a huge contribution to Sumimoto and supporting his bid to become the head of the HOSOKAWA family (Confusion of Eisho).
永正4年（1507年）6月、政元が澄之派の重臣・香西元長や薬師寺長忠らによって殺されると、8月に澄元は澄之討伐の兵を挙げたが、このときに高国は澄元を支持して討伐に貢献し、澄元の家督相続を承認した（永正の錯乱）。