When the Korean Navy, led by Yi Sun-shin, attacked 場門浦 in October 1594, Masanori himself went into the sea and conducted his army, and repelled the enemy force by setting fire to their ships (Seikanroku, or the Record of Subjugation of Korea) (from Chiefs of Staff 'Chosen-eki').
文禄3年（1594年）10月に朝鮮水軍を率いる李舜臣が場門浦を攻撃した時（場門浦海戦）には正則自ら海水に下りて指揮を行い、敵船を焼き討ちするなどの反撃でこれを撃退した（征韓録）（参謀本部「朝鮮役」より）。