After shooting the first arrow in the war between Yoritomo and the Taira clan, Tsunetaka fought with his elder brother, Sadatsuna SASAKI, using swords and finally killed Nobuto.
頼朝と平氏との戦いにおける最初の一矢を放った後、太刀を抜き戦い、兄の佐々木定綱と共に信遠を討つ。