Sam-a began fighting at age 9 after following the career of his uncle and watching Muay Thai on TV.

Following a loss to Captainkane Narupai, Sam-A would stop top-tier fighters, Jenrop Sakhomsin, Penek Sitnumnoi, and Rungruanglek Lukprabart all in a row.

Sam-a continued his great run of fighting in 2009 by starring in a classic rivalry with fan favorite, Pornsanae Sitmonchai.

For his first fight of 2012, he defeated Rungruanglek Lukprapbart by unanimous decision, and in doing so may have finished a long rivalry between the two with a 4–3 record head-to-head.

On May 4, Sam-A fought Penake Sitnumnoi at Lumpinee Stadium with the winner expected to receive the prestigious Fighter of the Year award.

[7] During the fight, Sam-A suffered a thigh injury which caused him to stop training Muay Thai and turn to boxing instead.

He made his Muay Thai comeback on August 6 and defeated Tong by unanimous decision at Lumpinee Stadium.

[14] Sam-a beat Superlek Wor Sangrapai on points to win the vacant Thailand super bantamweight title at Lumpinee Stadium on July 12, 2013.

On January 26, 2018, he faced Joseph Lasiri at ONE Championship: Global Superheroes in the promotion's first-ever Muay Thai contest, defeating the Italian via second-round TKO.

[19] Following his title loss, Sam-A Gaiyanghadao moved down to strawweight and eventually made his return to ONE Championship on October 13, 2019, at Tokyo.

[24] Sam-A was then scheduled to make his first defense of the ONE Strawweight Muay Thai World Championship against Josh Tonna, who was coming off a two straight wins.

Coming into the fight as a huge favorite, Sam-A defeated Tonna via second-round TKO after delivering three knockdowns to retain the title.

[27] In February 2022, it was reported that Sam-A had retired from international competition after returning to Thailand from Singapore, where he had coached at Evolve MMA.

[28] Chitinat Asadamongkol, president of ONE Championship Thailand, stating that organization has never released news that Sam-A will retired and Sam-A himself is still in the contract, but who went back to fight with Petchyindee battle earlier, because Nuttadaj contacted him to negotiate and there is a discussion which organization allows, with matters of this nature having to be discussed on a case-by-case basis.

[29] After won Tongnoi Lukbanyai and Samingdam Chor.Ajalaboon at Petchyindee in Rajadamnern Stadium, Sam-A faced Ryan Sheehan on March 17, 2023, at ONE Friday Fights 9.

[31] Sam-A faced Prajanchai P.K.Saenchai in a rematch at ONE Friday Fights 22 on June 23, 2023, for the interim ONE Muay Thai Strawweight Championship.