Sor Ploenchit was born as Somchai Chertchai (สมชาย เชิดฉาย; nickname: Neng; เหน่ง) in Amphoe Thanyaburi, Pathum Thani province.
[2] On February 13, 1994 he beat David Griman in Chachoengsao province, got the world champion title, defending it several times from famous boxers such as Jesús "Kiki" Rojas, Aquiles Guzmán, Kim Yong-kang, and Danny "Bazooka" Núñez.
After the bout, King Bhumibol Adulyadej also sent a royal congratulatory letter to him and his team through the Thai Consulate in Osaka.
His final fight, lost by TKO in the 6th round, was with Joichiro Tatsuyoshi, a Japanese former two-time WBC Bantamweight world champion, in late 2002.
[2] After retirement, Sor Ploenchit's life went downhill, more than half the gold necklaces acquired during his glory days being revealed as fake.