According to 56-year-old Barney Salazar, Natasha Davis became upset when he asked her to quiet down.
"She came running down and said, 'you wanna go Barney?' I noticed she had a big samurai sword," Salazar said. "I was very mad, when I seen her come out like that. With my granddaughter right there, that's what really upset me."
The 24-year-old allegedly swung the sword at Salazar multiple times before her boyfriend was able to restrain her. Salazar's 14-year-old granddaughter was also present for the incident.
"I think her boyfriend stepped in just in time and was able to hold her back, so there was no further assault," Salt Lake Police Sgt. Robin Heiden told KUTV.
Salazar blocked one of the sword swipes with his arm and sustained a three-inch slash on his left forearm that required 10 stitches.
Davis is being held without bail.