Songchainoi was scheduled to face
Phetsuphan Por.Daorungruang for the vacant S-1 Super Flyweight title on May 1, 2022. He won the fight by decision. In 2021, after a competition pause due to the covid-19 pandemic, Songchainoi went on a six fights winning culmainating on July 9, 2022, in a decision win against Yoknungdej Phetsithong at the Omnoi Stadium. On September 25, 2022, Songchainoi travelled to Japan to face
Momu Tsukamoto at NJKF West 4th - 1st Stage. He won the fight by a first-round technical knockout, as he was twice knocked down with a right cross before the referee stopped the bout.
ONE Championship Songchainoi made his
ONE Championship debut at
ONE Friday Fights 2 against Yoddoi Kaewsamrit on January 23, 2023. He won the fight by unanimous decision but suffered broken fingers during the bout which required surgery. Songchainoi returned to Japan on April 9, 2023, to faced
Nadaka Yoshinari at BOM Ouroboros 2023. He lost the fight by third technical knockout after three knockdowns. Songchainoi's third fight in Japan happened on July 9, 2023, when he faced Jurai Ishii at BOM 41. He won the fight by majority decision. On September 22, 2023, Songchainoi faced
Jomhod Eminentair at
ONE Friday Fights 34. He won the fight by second round technical knockout.. After this result Songchainoi was ranked as the #1 muay fighter in the world at 115 lbs by the WBC Muay Thai. On April 6, 2024, Songchainoi faced Nicolas Leite Silva at
ONE Fight Night 21. He won the fight by unanimous decision. On December 20, 2024, Songchainoi faced Yodnumchai Fairtex at
ONE Friday Fights 92,. He won the fight by second knockout. He received a 350,000 baht bonus for his performance. On March 14, 2025, Songchainoi faced Teeyai P.K.Saenchai at
ONE Friday Fights 100. He won the fight by unanimous decision. Songchainoi was scheduled to face
Numsurin Chor.Ketwina at
ONE Friday Fights 122 on August 29, 2025. Before the bout he was on a 9 fight winning streak inside the promotion. He lost the fight by majority decision after receiving an eight count. Songchainoi faced Salai Htan Khee Shein at
ONE Friday Fights 130 on October 24, 2025. He won the fight by unanimous decision. Songchainoi was scheduled to challenge
Nadaka Yoshinari for his
ONE Atomweight Muay Thai World Championship at
ONE Samurai 1 on April 29, 2026.. He lost the fight by unanimous decision. ==Titles and accomplishments==