¶1The issue in this case at the close of the. evidence was very simple. The plaintiff claimed that the *190defendant struck and seriously injured her without provocation ; the defendant, while admitting that he struck the plaintiff, claimed that his act was in rightful self-defense. The defendant’s claim as set forth in his answer, that he used sufficient force only to remove the plaintiff from his father’s sick-room, practically dropped out of the case because the plaintiff’s claim to recover was based entirely on a blow or blows which were not any part of the alleged removal from the sick-room.
¶2The law unquestionably is that where, as in this case, the defendant admits the blow, but claims that his act was justified by the law of self-defense, he has the burden of proving the facts which show that he acted in proper self-defense. Monson v. Lewis, 123 Wis. 583, 101 N. W. 1094, and cases cited; 5 Corp. Jur. p. 664, § 102.
¶3The conflict in the evidence was very sharp on the question as to who was the aggressor in the fracas, and under such circumstances an instruction which places the burden of proof on the wrong party on the main issue in the case must be deemed in all ordinary cases to affect the substantial rights of the party. Carle v. Nelson, 145 Wis. 593, 130 N. W. 467.
¶4By the Court. — Judgment reversed, and action remanded for a new trial.