Yoshikiyo suffered a crushing defeat as supreme commander by the Taira clan's army who were accustomed to fighting on ships, and along with Yukihiro UNNO, his younger paternal half-brother Yoshinaga and many others, he was killed in a fierce battle from a barrage of falling arrows (the battle at Mizushima).
総大将の義清は船戦に慣れた平氏軍を前に大敗を喫し、海野幸広や同母弟の義長らとともに矢の雨に浴びせられて、壮絶な戦死を遂げた（水島の戦い）。