Petchsamarn debuted his career in Bangkok under the name Newsaenchai Pakornphonsurin. At the end of 2017, following a series of losses he went back to compete in the provinces, at this occasion he changed his ring name to Petchsamarn Sor.Samarngarment. He went on an extended win streak throughout 2018 that led him to be picked up by the Kiatpetch promotion back in Bangkok.[citation needed]
On October 8, 2019, Petchsamarn defeated two weight Lumpinee Stadium champion Kompetch Sitsarawatsuer by decision.[3] The following month he defeated three weight Lumpinee Stadium Champion Ronachai Tor.Ramintra by decision, taking his win streak to nineteen in a row and cementing his position as an elite fighter in the 122 lbs division.[4]
Petchsamarn's undefeated streak came to an end when he was defeated by decision in a fight against Prajanchai P.K.Saenchaimuaythaigym on December 6, 2019 [5] They rematched with the vacant Lumpinee Stadium 122 lbs title at stake. Petchsamarn lost the fight by decision again.[6]
Following his title fight defeat Petchsamarn lost five fights in a row. He was defeated by decision against Chaila Por.Lakboon, Kompetch Sitsarawatsuer and Saoek Sitchefboontham.[7] His losing streak reached its lowest point when he was stopped by Boonlong Petchyindee in the second round on October 9, 2020, at Rangsit Stadium for the Muaymanwansuk promotion.[8]
Back to competition after a nine-month break due to the COVID-19 pandemic, Petchsamarn faced Petchmaeprik Fordpayakdaennua for the vacant Channel 7 Stadium 122 lbs title on December 12, 2021. He won the fight by decision.[9] Petchsamarn failed to protect his title on May 22, 2022, when he was defeated by Parnthep V.K.Khaoyai.[10] They rematched in a non-title fight on January 7, 2023, at the World Siam Stadium. Petchsamarn won the bout by decision.[11]
On March 12, 2023 Petchsamarn faced Decho Por.Borirak at the Channel 7 Stadium. He won the fight by unanimous decision.[12]
