Narantungalag had a slow start to his mixed martial arts career, losing his first two professional bouts to UFC veteran Norifumi Yamamoto in 2004, and Toshikazu Iseno in 2006, via KO and unanimous decision respectively.
[2][3] Following this though, he would go on a four fight winning streak, and also won the Mongolian MMA Championship Tournament in 2010, defeating both Burenzorig Batmunkh and Otgonbaatar Nergui via submission.
After signing with the promotion, Narantungalag faced Pride FC and UFC veteran Akihiro Gono at WVR: Sengoku Raiden Championships 14 on August 22, 2010.
[10] In his first title defense within the promotion, Narantungalag faced Korean prospect Yui Chul Nam at Legend FC 8 on March 30, 2012.
[16] Narantungalag faced Koji Oishi for the ONE Featherweight Championship at ONE FC 19: Reign of Champions on August 29, 2014.
Following a forced hiatus due to injury, Jadambaa returned in 2018 and picked up back-to-back victories over Edward Kelly and Kazuki Tokudome.