Overview
Yi Sak Lee (이이삭), also known internationally as Lee Yi Sak, was born on January 11, 2000, in South Korea.
Standing 6’0″ (183 cm) with a 74-inch (188 cm) reach, he competes in the middleweight division while representing Korean Top Team in Seoul. Yi Sak Lee made his professional debut in 2021 and quickly established himself as one of the fastest-rising prospects in the Korean regional scene.
Before signing with the UFC, Lee compiled an 8-1 professional record, earning victories in Top Fighting Championship (TFC), Double G FC, WKG & M-1 Global, Dragon FC Longsan Fight, and HEAT. His performances across Korea, China, and Japan demonstrated that he could consistently compete outside his home country against increasingly experienced opposition.
His momentum culminated in a UFC contract, making him one of the newest Korean fighters to reach the Octagon. Although he lost his promotional debut in May 2026, Lee remains in the early stages of what many believe could become a successful international career.
Early Life & Background
Public information regarding Yi Sak Lee’s childhood is limited, but his martial arts background is well established. He began training in judo at the age of 11, developing the balance, body control, and grappling instincts that would later become defining aspects of his MMA game. According to Lee, he decided to pursue mixed martial arts after watching an MMA event as a teenager and believing he could compete at that level.
Yi Sak Lee eventually joined Korean Top Team, where he trained alongside UFC veterans and some of South Korea’s top professional fighters. The gym’s emphasis on complete mixed martial arts helped him expand beyond his judo background, developing effective boxing, wrestling, and submission skills that complemented his natural athleticism.
His progression through the amateur ranks was brief. After showing promise in amateur competition, Yi Sak Lee transitioned to the professional circuit in 2021 and immediately demonstrated that he possessed the physical tools to compete with experienced opponents despite his relative inexperience.
Fighting Style
Yi Sak Lee’s foundation is judo, but his overall style has evolved into that of a complete mixed martial artist. His explosive athleticism allows him to dictate where fights take place, whether through aggressive striking exchanges or grappling transitions.
His professional victories include:
- 4 wins by KO/TKO
- 3 wins by submission
- 1 win by decision
Those numbers illustrate a fighter with genuine finishing ability. Lee has earned knockout victories through heavy ground-and-pound and powerful striking combinations, while his submission game includes rear naked chokes and a notable Von Flue choke, showcasing technical awareness beyond his years.
Standing six feet tall with a long reach for the division, Yi Sak Lee uses his physical attributes effectively. He is comfortable applying forward pressure, creating scrambles, and capitalizing on opponents’ mistakes rather than simply waiting for counterattacking opportunities. His willingness to pursue finishes has become one of the defining characteristics of his career.
Professional Career
Yi Sak Lee made his professional debut at TFC Dream 7 in July 2021, stopping Hyo Sung Eun by first-round TKO. He followed that performance with another first-round stoppage of Kyung Min Cho at TFC 20, quickly establishing himself as one of Korea’s top middleweight prospects.
His reputation continued to grow after victories in Double G FC, WLF MMA, and GLADIATOR, including a unanimous decision over Danier Nuerboli, the only decision victory of his professional career before reaching the UFC. Lee later scored consecutive stoppage victories over Shota Fujii, Aerdake Apaer, Weichao Nie, and Daichi Henry Mikami, steadily climbing the regional rankings.
One of the biggest tests of his career came in December 2024, when he faced former ONE Championship title challenger Agilan Thani at Breakthrough Combat 2. Lee suffered the first defeat of his professional career via second-round rear naked choke. Rather than allowing that loss to derail his momentum, he rebounded with two impressive submission victories, demonstrating maturity and resilience uncommon for a young prospect.
Those performances earned Yi Sak Lee a UFC contract. He made his promotional debut at UFC Fight Night on May 30, 2026, facing Brazilian middleweight Luis Felipe Dias. Although Lee lost by first-round TKO, reaching the UFC after only nine professional fights highlighted both his potential and the rapid pace of his development.
Career Highlights
- Professional record of 8-2.
- Represents Korean Top Team.
- Professional debut in 2021.
- UFC middleweight competitor.
- Background in judo, beginning training at age 11.
- Earned victories in TFC, Double G FC, GLADIATOR, WKG & M-1 Global, Dragon FC Longsan Fight, and HEAT.
- Holds victories over Daichi Henry Mikami, Weichao Nie, Shota Fujii, Aerdake Apaer, and Danier Nuerboli.
- Seven of eight professional victories have come by finish, highlighting his aggressive style.
Summary & Trajectory
Yi Sak Lee represents the next generation of Korean middleweights. While many Korean fighters spend years building extensive regional résumés before earning opportunities abroad, Lee reached the UFC less than five years after turning professional. His rapid rise reflects a combination of physical talent, technical development, and consistent finishing ability.
Although his first UFC appearance ended in defeat, Yi Sak Lee remains one of South Korea’s most intriguing young prospects. With a strong judo background, improving striking, and the support of Korean Top Team, he possesses many of the attributes needed to develop into a long-term competitor at the highest level. At only 26 years old, his best years are likely still ahead of him.
Yi Sak Lee is one of the most promising middleweight prospects to emerge from South Korea in recent years. Still in his mid-20s, Lee has rapidly climbed from the Korean regional circuit to the UFC through a combination of explosive finishing ability, physical tools, and a strong judo foundation. Representing Korean Top Team, he has developed into a dangerous finisher with the size and athleticism to compete against high-level international competition.
Unlike many young prospects who rely solely on athleticism, Lee has demonstrated a balanced offensive arsenal. His professional victories include knockouts, submissions, and a composed decision win, while nearly all of his finishes have come before the final bell. That ability to consistently end fights has made him one of Korea's most exciting rising talents.
Although his UFC debut resulted in a setback against Luis Felipe Dias, Lee reached the world's premier MMA organization with fewer than ten professional fights—a testament to both his potential and the confidence matchmakers had in his future. At just 26 years old, he remains one of the brightest long-term middleweight prospects in Korean MMA.
Sang Kwon Han
Dae Hwan Kim
Yong Soo Jung
