Who is “Baby Shark”?
Facing Daiki Yonekura on One Championship - ADCC Two-Time Champion and His Rivalry with Diego “Pato” Oliveira
Article Information
On December 6 in Bangkok, Diogo “Baby Shark” Reis will face Daiki Yonekura at ONE Championship. Reis is one of the best lightweights in the world today, having won the ADCC 66 kg division in both 2022 and 2024, and has also collected multiple major titles in gi jiu-jitsu. In this article, we’ll look back at his career so far, focusing mainly on his no-gi/grappling achievements.
Short Bio
Diogo Reis, known as “Baby Shark,” was born on March 20, 2002 — just 23 years old at the time of writing. Even at that age, his résumé already stands out among current lightweight grapplers.
Born and raised in Manaus, Brazil’s seventh-largest city, he trained under Melqui Galvão (Mica’s father) alongside fellow Manaus stars Mica Galvão and Fabricio Andrey, learning jiu-jitsu, luta livre (Brazilian catch-style grappling), and wrestling. He received his BJJ black belt from Melqui in 2020.
In gi competition, he has placed 2nd at the IBJJF Worlds and won the Pan and European Championships, but it’s in grappling that he’s really stamped his name — above all by winning the ADCC World Championships at 66 kg in both 2022 and 2024.
In FloGrappling’s documentary “The Ups & Downs of the Manaus Boys,” you can see what life in Manaus looks like and how they train. Melqui’s gym operates in a semi-boarding style — the athletes, including children, live and train there during the week, then return home to their families on weekends. The team name and affiliation (e.g., Dream Art, Fight Sports) have changed over time, but the core remains the same, with training methods unchanged.
One thing that really stands out is how seriously they train wrestling — wearing wrestling shoes and drilling as a separate discipline, not just as an offshoot of jiu-jitsu.
vs. Noah Wyatt (Third Coast Grappling)
As far as we can confirm in his grappling career, the last (and in fact the only) submission loss at black belt — apart from a later injury retirement — came on June 20, 2021, against Noah Wyatt. He was caught with an inside heel hook from the saddle after Wyatt entered off a false reap. Watching that match, you realize Baby Shark wasn’t always this untouchable. Considering that he won ADCC the very next year, the speed of his evolution is remarkable.
vs. Gabriel Souza (2022 ADCC Final) – First ADCC Title
After beating Diego “Pato” Oliveira in the ADCC Trials final, Baby Shark went on an incredible run at ADCC 2022:
- Rd 1: beat then-Polaris champ Ashley Williams
- Rd 2: beat his training partner and “brother” Fabricio Andrey
- Rd 3: beat Josh Cisneros
to reach the final against Gabriel Souza.
In the final, after a back-and-forth battle with wrestling, leg entanglements, guard exchanges and passing attempts, Baby Shark finally took the back and secured the win — capturing his first ADCC title.
That final is an excellent example of his game: not flashy for the sake of flash, but constantly working, dangerous in every phase, and with no apparent weaknesses. In the match with Fabricio, he even let him stand back up from turtle to re-take the standing back position and secure the type of sequence that scores well — a good example of his high mat IQ.
vs. Diego “Pato” Oliveira (WNO 21) – His Last Loss in Grappling
You can’t talk about Baby Shark without talking about Diego “Pato”. Pato is another elite, submission-hunting lightweight. Like Reis, he’s from Manaus, but unlike Reis and the Galvão group who stayed in that system, Pato moved to São Paulo to train under Cicero Costha and now represents AOJ (Art of Jiu-Jitsu) in the U.S.
The two have met many times — in ADCC Trials, IBJJF Worlds, Pans, and other major finals.
At WNO in 2023, Baby Shark was forced to withdraw mid-match due to injury, giving Pato the WNO title. As far as we can verify, this is Baby Shark’s last loss in grappling.
vs. Diego “Pato” Oliveira (2024 ADCC Final) – Revenge and a Second ADCC Title
Coming in as the defending champion in 2024, Baby Shark beat:
- Shu Huaichen, Asia–Oceania Trials winner, in round 1
- Fabricio Andrey again
- Josh Cisneros again
to reach the final.
On the other side of the bracket, Pato defeated Ashley Williams, Ethan Crelinsten, and Owen Jones to set up the long-awaited rematch.
In the final, Pato was actually ahead in the early exchanges: when Reis moved to a north-south position, Pato entered K-guard, came up through the club ride, and hit a sweep. From half guard, he passed; from double guard, he attacked with footlocks, knee bars, and back takes. But he couldn’t finish.
Reis escaped a heel hook, brought it back to the standing/sitting battle, and this time, he was the one pressuring with guard passes. Pato tried to counter with leg entries, but Reis eventually body-locked, took advantage when Pato briefly showed his back, locked up a head-and-arm (kata-gatame) style grip and finished — securing his second straight ADCC title.
After that, the two met again in the IBJJF Worlds final, where Pato took the win by referee decision — so the rivalry is very much ongoing.
vs. Shoya Ishiguro (ONE Championship 2025)
In 2025, Reis faced Shoya Ishiguro of Carpe Diem at ONE. Early on, he showed some aggressive top passing — throwing the legs aside, hunting an Estima lock from top. Then he switched to headquarters, built his grips, jumped on a kimura and locked in the “scissor” position. Ishiguro tried to roll out, but Reis followed and finished the kimura.
Note: Reis missed weight for this bout; it was changed from flyweight (61.2 kg) to a 63.2 kg catchweight.
Final Thoughts
In this article, we looked back at the grappling career of Diogo “Baby Shark” Reis from the time he got his black belt. With him now set to face Daiki Yonekura at ONE Championship on December 6, it’ll be fascinating to see how Japan’s rising star matches up with arguably the best lightweight grappler on the planet right now.
