In the midst of this campaign, his uncle Noriyuki OUCHI, at the instigation of the Shoni and Hosokawa clans, raised a rebellion in Shimonoseki and Masahiro sent Hiromori SUE back to put it down.
そのさなか、1470年（文明(日本)元年）に少弐氏、細川氏らに使嗾された叔父大内教幸が下関で謀反を起こし、政弘は討伐のために陶弘護を帰国させる。