The incident unfolded shortly after midnight at Lao Gao Di Guo Ji, a Chinese restaurant located in Bang Lamung District, Pattaya, according to local authorities, as reported by the Bangkok Post.
Pattaya police, responding swiftly to the emergency call, found the 40-year-old victim suffering from a stab wound.
He received immediate first aid on-site before being transported urgently to a nearby hospital, said Lieutenant Colonel Suchart Dusadee, according to Khaosod.
The suspected attacker, identified as He Wen Qiang, was apprehended by police at the restaurant. Officers also recovered a fruit knife from the scene, believed to be the weapon used in the assault.
Witnesses said the victim had been drinking with friends in a private room when He mistakenly entered. When asked to leave, He, visibly intoxicated, reportedly pulled out a knife and attacked the victim.
Authorities continue to investigate the circumstances surrounding the incident.