A home invader killed a woman with her own samurai sword during a bizarre midday attack in Southern California, authorities said.

A 40-year-old woman and a male pal, 42, were at her home in the Los Angeles suburb of Temple City when the 44-year-old assailant broke in through an unlocked front door at 12:05 p.m. on Wednesday, sheriff’s deputies told the San Gabriel Valley Tribune.

The violent lunatic attacked the woman with a wrench he brought with him, and then grabbed a decorative samurai sword hanging on a wall to finish her off, authorities said.

The victim’s male friend was also injured in the attack but is expected to survive. The woman’s 10-year-old son was also in the house but wasn’t hurt.

About two hours later, the suspect surrendered to deputies, officials said.

He appeared to be under the influence of drugs or booze, deputies told KABC-TV.

Deputies recovered the murder weapons but the killer’s motive wasn’t immediately clear.