With this, he earned a rematch with Yuki and a shot at the RISE Lightweight (-63 kg/138.9 lb) Championship in the main event of the RISE 91/M-1 ~Infinity II~ co-promotion on January 6, 2013. The fight went very much like their first encounter, where Lee used his advantage in speed and combinations to score on Yuki, particularly with low kicks that damaged the more powerful striker and led to a stoppage in round four and captured Lee the title as well as the #4 place in the world lightweight rankings. He then moved up to -70 kg/154 lb and returned to K-1 after a two-year absence to compete in the K-1 Korea MAX 2013 eight man tournament in Seoul on February 2, 2013. Drawn against Shingo Garyu in the quarter-finals, he scored a low kick knockdown over his Japanese opponent in round two before completely taking over in three. Lee dropped him again with a right cross after hurting him with a body shot and at times simply teed off on Garyu who was content to block punches with his face. Having won by unanimous decision, he then went up against Zheng Zhao Yu in the semis and won via TKO with a front kick to the body in the second round after forcing a standing eight count earlier. Pongthong Jetsada awaited him in the final, and Lee outpointed the Thai to win a unanimous decision and take the tournament crown. He remained at -70 kg/154 lb for his next outing as he made his Glory debut against Yoshihiro Sato at Glory 8: Tokyo - 2013 65kg Slam on May 3, 2013. Giving up 12 cm/4 inches in height, Lee lost to Sato by unanimous decision in a close match. Lee dropped to 65 kg/143 lb to fight RISE's super lightweight title holder Yasuomi Soda in a non-championship bout at RISE 94 on July 19, 2013. Soda was shown a yellow card after low blowing Lee twice in round one but stormed back to win a majority decision and stop Lee's five-fight winning streak in the promotion. Having qualified for the tournament with his K-1 Korea win, Lee beat Charles François by unanimous decision after scoring a first round knockdown at the K-1 World MAX 2013 World Championship Tournament Final 16 in Majorca, Spain on September 14, 2013.