ONE Championship recently announced that it has signed 18-year-old Brazilian jiu-jitsu phenom Helena Crevar of the United States to compete in its submission grappling division. View this post on Instagram Instagram PostShe will join fellow grappler Jessa Khan in ONE, as well as reigning ONE women's atomweight submission grappling world champion Mayssa Bastos.The Las Vegas-born athlete made history last year as she became the youngest competitor to finish on the ADCC World Championship podium, earning a silver medal at the age 17.The Texas native now trains under renowned grappling and MMA coach John Danaher at his New Wave Team facility in Austin, where she relocated at the age of 15 to pursue elite-level training alongside the likes of Garry 'The Lion Killer' Tonon and Gordon 'King' Ryan.After exactly a decade in the sport, Crevar was awarded her jiu-jitsu black belt in June 2025, and now she brings her world championship pedigree to the world's largest martial arts organization.Among Crevar's most notable accomplishments include recently winning the Polaris 70-kg title in 2024 and capturing multiple IBJJF World Championship and IBJJF Pan Championship titles across various belt levels.Crevar's signing to ONE also adds another young prospect to the promotion's growing submission grappling roster. ONE has yet to announce when Crevar will make her debut, but stay tuned to Sportskeeda MMA for all the latest updates.Helena Crevar's most notable achievementsMain Achievements (Pro Level):Polaris 70 KG Title (2024)1st Place ADCC West Coast Trials (2024)2nd Place ADCC World Championship (2024)2nd Place ADCC East Coast Trials (2024)Main Achievements (Colored Belts):1st Place IBJJF World Championship (2025 brown)1st Place IBJJF Pan Championship (2025 brown)F2W 150lb Gi Blue Belt Title (2024)F2W 145lb Gi purple Belt Title (2023***)Main Achievements (Juvenile):F2W 145lb NOGI Teen Title (2021-2022)1st Place IBJJF World Championship (2023**)1st Place IBJJF World Championship NOGI (2023** / 2024)1st Place IBJJF Pan Championship (2023** / 2024**)1st Place IBJJF Pan Championship NOGI (2023)1st Place AJP Abu Dhabi World Pro (2023)