Joo Sang Yoo Fights to Stay Undefeated at UFC 320
By James Moreau | 04 Oct, 2025

After a stunning 28-second knockout in his UFC debut, undefeated Korean fighter Joo Sang Yoo, "Zombie Jr.," prepares to face ranked opponent Daniel Santos.

Korean MMA featherweight fighter Joo Sang Yoo holds an undefeated professional record of 9 wins and 0 losses since his 2021 debut.

His nickname “Zombie Jr.” pays homage to retired Korean UFC fighter Jung Chan-sung whom Yoo credits with the realization of his UFC dreams.  The “Zombie” plays to their aggressive fighting style, continuing to move forward even after absorbing heavy blows.

Yoo made his UFC debut on June 7, 2025 against Jeka Saragih in UFC 316, knocking him out in just 28 seconds.  His electric appearance earned a $50,000 performance of the night bonus.  

His professional record of 4 knockouts, 1 submission, and 4 unanimous decisions has secured the 31-year-old a number 116 ranking in the featherweight division. Yoo’s second UFC appearance is scheduled for October 4, 2025 at UFC 320 in Las Vegas against 55th ranked Daniel Santos.   Sportsbooks give slight edge to Santos with Draft Kings -142 being the biggest outlier.  Though both orthodox fighters stand 5’7” Yoo outreaches Santos by 4” favoring his boxing tendencies.