When you talk about the best pound-for-pound grapplers on the planet, there's one name that simply has to come up: Diogo "Baby Shark" Reis.
At just 24 years old, the reigning ONE Flyweight Submission Grappling World Champion has already built a career that commands respect at the highest levels of the sport. And he's about to step back into the spotlight.
Reis returns to action at ONE Fight Night 43: Tang vs. Gasanov, streaming live on Prime Video from Bangkok's legendary Lumpinee Stadium on Friday, May 15. This time, he's moving up to bantamweight to face Japanese rising star Yuki Takahashi. It's a bold move for a fighter who's already proven he can hang with the best.
Hailing from Manaus, Brazil—a city that's practically hallowed ground for Brazilian Jiu-Jitsu—Reis has built a resume that rivals athletes who've spent decades on the mats. He's been competing globally since his teenage years, stacking up multiple IBJJF World Titles and two ADCC World Championship crowns. His career record? A staggering 94-9 across both gi and no-gi competition.
That elite pedigree followed him straight into the world's largest martial arts organization, where he made an immediate, undeniable impact. Just two wins into his ONE Championship run, and he already owns 26 pounds of undisputed gold.
Before he chases a second World Title at bantamweight, let's take a look back at the performances that built the legend of "Baby Shark."
From the moment he signed with ONE, all eyes were on Reis. As one of the most highly anticipated additions to the promotion's grappling ranks, he carried the weight of enormous expectations. His first major test came at ONE Fight Night 29 in March 2025, where Shoya Ishiguro proved to be no easy introduction. The Tokyo-born Carpe Diem black belt had gone unbeaten in three ONE outings and believed he could knock off one of the sport's brightest young stars.
But for a two-time ADCC World Champion, the bright lights are nothing new. Reis thrives under pressure, and he's shown time and again that he's built for the biggest moments.
Whether you're a longtime fan or just discovering the sport, one thing is clear: Diogo Reis is an apex predator in the making, and his journey is only getting started.