Jan Cooper said at a news conference that she fired one shot from her high-powered handgun, according to a report in KTLA-TV Channel 5.
Cooper and husband, a disabled World War II veteran, were alone at the home Sunday when she loaded her gun and dialed 911 as the man allegedly tried to force his way in.
On the 911 tape, Cooper can be heard telling the man to leave.
"Get the hell out of here," she said. She told the dispatcher that she was going to shoot at the man. "I'm firing!" she said, as sound of the gunshot broke out.
The suspect, identified by authorities as Brandon Alexander Perez, 31, was not hit. He was arrested a short while later.
Perez was on parole for a burglary conviction, the Orange County Sheriff's Department said.
Cooper said she had a message for Perez: "You have no idea how lucky you were to be able to walk away from my house and not have to be carried out."