SAN DIEGO -- Twenty-six nations from around the world gathered earlier this month for the first-ever youth mixed martial arts world championships held in Rome, Italy.
The United States took home 16 gold medals and won first place overall -- and one of those gold medalists came right out of San Diego's South Bay.
A self-described "quiet" teenager, Sergio Porras isn't one for boasting his accomplishments.
"I don't like to show off," said Porras. "I just want to stay humble."
The 13-year-old recently became a world champion after winning all three of his matches in the youth MMA world championships, a first-of-its-kind tournament under the International Mixed Martial Arts Federation.
"To witness him go against countries like Ukraine, Bulgaria -- and he also fought against the United States -- and for him to become victorious with two submissions and one complete domination, I'm just speechless," coach Joe Nuñez said. "I'm very happy."
"That gave me quite a bit of confidence because now I know that I'm good enough to compete against people from the other side of the world," Porras said.
The 106-pound eighth grader specializes in jiu jitsu, a form of self defense that doesn't require the act of hurting your opponent.
"Not only does he do jiu jitsu, but he also does kickboxing, he does wrestling. But his grappling, which is the art of wrestling in jiu jitsu, I would say is his strong point," said Nuñez.
After trying his hand at several other sports, Porras took up MMA when he was five years old, admitting he got into the contact sport as a way to learn self defense against bullies in school.
"In first grade I used to get bullied so my parents, they put me in mixed martial arts so I could defend myself and I learned a bunch of mixed martial arts and I solved the problem," Porras said.
As one of the top athletes in his class, the soft-spoken champion has become a role model to others, letting his actions speak for themselves.
"They're all just cheering me on since the beginning so I feel very happy to see all them smiling," Porras said.
"He holds a self of responsibility and he's stepping up to the plate and he's knowing that a lot of people are watching him and watching how he moves," Nuñez said.