The Rise Of An Apex Predator: Reliving Diogo Reis’ Dominant ONE Championship Run Ahead Of ONE Fight Night 43
Any discussion of the world’s absolute best pound-for-pound grapplers is simply incomplete without one specific name.
At just 24 years old, reigning ONE Flyweight Submission Grappling World Champion Diogo “Baby Shark” Reis has already assembled a body of work that demands ultimate respect across the highest levels of the sport.
Reis returns to the global stage at ONE Fight Night 43: Tang vs. Gasanov on Prime Video. The blockbuster spectacle broadcasts live in U.S. primetime on Friday, May 15, from Bangkok’s legendary Lumpinee Stadium, as the Brazilian sensation moves up to bantamweight to face Japanese rising star Yuki Takahashi.
Hailing from Manaus, Brazil — one of the most storied Brazilian Jiu-Jitsu hotbeds on the planet — Reis has built a resume that rivals athletes who have spent decades on the mats. Competing globally since his juvenile years, he has amassed multiple IBJJF World Titles and two ADCC World Championship crowns across a staggering 94-9 career record in both gi and no-gi competition.
That elite pedigree followed him directly to the world’s largest martial arts organization, where Reis made an immediate, undeniable impact. Just two victories into his ONE Championship run, the Brazilian already owns 26 pounds of undisputed gold.
Before he begins his pursuit of a second World Title at bantamweight, here is a look back at every performance that built the legend of “Baby Shark.”
Drawing First Blood
All eyes were fixed on Reis from the very moment he signed with ONE. As one of the most highly coveted additions to the promotion’s talent-stacked grappling ranks, the Brazilian arrived carrying 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 entered with genuine belief he could topple one of the sport’s most high-profile young stars.
However, for a two-time ADCC World Champion, the blinding spotlight was nothing new. Reis thrived under the immense pressure, attacking from the opening moments with explosive, side-to-side guard passing that kept Ishiguro perpetually off-balance and offered him absolutely no room to settle.
After effortlessly breaking through the guard, “Baby Shark” unleashed his full creative arsenal, jumping into a picture-perfect kimura lock while simultaneously trapping Ishiguro in a devastating head scissor choke.
He torqued the arm to a gruesome angle and forced the tap, delivering a promotional debut that was as technically flawless as it was emphatic.
A New King Is Crowned
That statement-making debut immediately positioned Reis as the undeniable frontrunner for the vacant ONE Flyweight Submission Grappling World Title.
The golden opportunity materialized at ONE Fight Night 38 last December, where the Brazilian faced Daiki Yonekura. The 29-year-old from Tokushima, Japan, brought polished positional grappling, sharp defensive instincts, and lightning-quick recoveries to a matchup that pitted his precision directly against Reis’ relentless aggression.
Reis came out with zero intention of letting the match breathe. Chasing the guard pass from the very first exchange, he broke through with a clean knee slice and locked in a deep arm-triangle choke from side control. Yonekura miraculously survived, but the relentless attacks never stopped coming.
In the final two minutes, Reis latched onto a tight guillotine before both men tumbled into chaotic leg entanglements, scrambling furiously for the finish. After ten minutes of suffocating, high-paced pressure, the judges awarded the unanimous decision to “Baby Shark.”
The most coveted hardware in submission grappling was finally his. Reis was crowned the new ONE Flyweight Submission Grappling World Champion and was later named ONE’s 2025 Submission Grappler of the Year — a highly fitting close to a simply stunning campaign.
On Friday, May 15, Reis tests the bantamweight waters against Yuki Takahashi, incredibly hungry to conquer new territory and add yet another thrilling chapter to a legacy that is still very much being written.
