What followed was a cacophony of barking and screaming that ended with the burglar retreating to a waiting getaway car. Brenda Romo, 20, who was home at the time, was unharmed.
"It was probably the scariest thing of my life," she said.
Now the family is hailing Patron as a hero for keeping the home and family safe.
"He gave my sister enough time to get out of danger," said Fernando Romo, 22, who also lives in the home.
The family says the incident also sheds some light on the positive side of pit bulls, a breed often involved in biting incidents. Pit bull-type dogs were involved in a third of dog bite incidents fatal to humans in a 20-year period from 1979 to 1998, according to a Centers for Disease Control study. That was more than any other breed type.
But those statistics mean nothing to Brenda. "He's a pretty good dog," she said.
Brenda was home alone on Tuesday morning after Fernando and his wife, Jasmin, had left for work, when she heard a loud banging on the front door. She saw a man at the door she didn't recognize. Brenda didn't answer the door, but later saw the same man walking through the backyard.
Minutes later, she heard a window shatter. She ran into a bedroom and grabbed an unloaded gun. Brenda fled into the bathroom and locked herself in, calling 911.
Brenda ran out of the house to safety and found a neighbor passing by.
It's unclear if Patron bit the man, or if the intruder simply became frightened at the sight of the hulking dog and fled.
Sheriff's deputies stormed the home on County Road 2952, but the intruder was long gone by then. No arrests have been made in the incident.
On Wednesday, broken glass was still visible and a tire iron lay nearby that Fernando believes was used to break the bedroom window.
The Romo family has had Patron for less than a year. Patron, who is about 2 years old, was bred by Levi Romero, owner of Sandstone Bullies, a Farmington breeder. Patron — Spanish for "boss" — is an American bully, a shorter, thicker type of pit bull.
"He's grown to be our best friend, and a savior for my sister," Fernando said.
Fernando said pit bulls can be excellent companions. "They're just a great breed," he said. "It just depends on how they're bred and treated."
Romero said pit bulls are too often portrayed negatively in the media.
"They're loving and loyal, and a couple of days ago they proved they're heroic in a way," he said. "All you hear in the media is bad stuff about them biting people."
Romero said he was surprised Patron scared off a burglar. "He's a wimp," Romero said.
Patron greeted a reporter visiting his home with a growl, but later grew playful. His powerful jaw makes short work of chew toys.
"He loves to eat a lot of tennis balls," Fernando said. "He'll destroy those things."
Members of the Romo family said Patron was more lap dog than guard dog before Tuesday's incident.
"He's so cuddly, and he's so friendly to everybody," Brenda said.
The Romos' other dog, a teacup-sized Yorkshire terrier named Chapo, was also home at the time. He wasn't much help during the break-in.
"He thought somebody was coming to play," Fernando said.
Chuck Slothower may be reached at firstname.lastname@example.org; 505-564-4638. Follow him on Twitter @DTchuck