Phoenix police say the teen was forced to stab his mother's boyfriend after the boyfriend went on the attack.
The man, identified as Keith Childress, exploded in anger and began beating the boy's mother before turning his rage towards that boy and his 15-year-old sister.
That's when the young man named Darvon grabbed a kitchen knife and fought back.
His mother told FOX 10 she had no doubt she would be dead or in a coma if it weren't for her brave son jumping into action and doing what he had to do to protect his mother -- by stabbing her boyfriend to stop him from a violent attack.
The 8th grade student was getting ready for school around 7 a.m. when Childress, who was visiting from out of town, began hitting and kicking her.
Police say when Darvon and his sister tried to stop Childress, he started beating them too.
"At that point, we have a 13-year-old that grabbed a kitchen knife and stabbed the suspect and stopped the confrontation at that point," said Sgt. Trent Crump.
Darvon says he just did what he had to do to protect his mother.
"It was my instincts, I had to stop it... I was a little bit nervous," he said.
Childress staggered, bleeding to a neighbor's front door.
"I opened the door and he literally like falls into the living room, and he's all that b**** stabbed me, that b**** stabbed me... and I looked the side.. he had a deep stab wound.. deep," said a neighbor.
"It was a bad situation and my son felt like the only way he could save my life was to do what he did. And he really saved my life. If it wasn't for him, I'd have been dead or in a coma. I'm sure of it. It was bad," said Darvon's mother.
Childress, 26, underwent surgery at an area hospital and is expected to survive his stab wounds. Police say he will face charges for domestic abuse.
As for Darvon, "Certainly a very brave young man this morning, and a decision you would hope that no 13-year-old or 15-year-old would have to make in this kind of case, but he has.. he seems to be okay," said Crump.
Darvon's mother says she is extremely proud of her son and it just so happens, he wants to be a police officer when he grows up.