 Suthep worked as a sign painter for about two years after graduating, until a friend invited him to voice act in a radio play he was writing.He was then introduced to composer/songwriter , and subsequently left the painting job to became Salai's apprentice.He began singing during play interludes, and became acquainted to several composers and songwriters, including , who offered Suthep his first recording opportunity with the song "Duangchai Thi Ro Khoi" (, 'Awaited Sweetheart'), and and , who wrote "Rak Khun Khao Laeo" (, 'Falling in Love with You'), the hit song that propelled Suthep to national fame in 1954, at the age of nineteen.