Jiu jitsu champion William Wilson began training with Sensei Christian Grandi when he was four years old.

NAPILI — Seventeen-year-old William Wilson of Napili is a jiu jitsu world champion.

Training at the Carlson Gracie Jiu Jitsu Lahaina club under Sensei Christian Grandi since he was four, the youthful martial artist has risen to green belt status — the equivalent to black belt ranking for jiu jitsu youth students — and is a multiple champion throughout his young years.

He has competed in the North American Grappling Association and has multiple titles in state and regional tournaments in gi and no gi competitions.

The world title came at the International Brazilian Jiu Jitsu Federation World Championships at the Anaheim Convention Center on Dec. 8-12.

Wilson won the gi world championship last year and completed the sweep with the no gi title two weeks ago.

Sensei Grandi described Wilson as very disciplined and respectful, with his dad having a military background and home schooling with his three siblings by his mom.

“He is a very determined and responsible person who sends a terrific message for all of the other kids around him. He has always been very consistent and interacts fluidly with the other students,” he said.