Police said the attack, believed to have been driven by jealousy, left the victim critically injured.
Kathu Police were called to The Scene Condominium at about 6:45pm after reports of a “stabbing” inside the condo complex in Kathu.
Responding officers found 39-year-old Kriengkrai Kajkla, a Phuket resident, suffering from two knife wounds to the temple. Rescue workers provided emergency assistance before rushing him to Vachira Phuket Hospital for urgent treatment.
Police said doctors later confirmed the wounds had damaged nerves and that the victim remained under close medical supervision.
According to Kathu Police, CCTV footage and witness statements showed that the victim had arrived at the condominium with his girlfriend, who owned a unit at the property.
Police allege that girlfriend later went to meet 33-year-old Sriwallop Phuengrang, from Phang Nga, at the elevator entrance before the pair went to the second floor.
Investigators said Sriwallop then encountered Kriengkrai hiding near a stairwell. During the confrontation, Sriwallop allegedly grabbed Kriengkrai by the shirt collar and struck him twice on the temple with a pocket knife.
Despite his injuries, Kriengkrai reportedly managed to run to the condominium management office for help, where staff contacted police.
While investigators were searching for the suspect, Sriwallop later surrendered to Kathu Police and allegedly confessed to the attack.
He was initially charged with assault causing serious injury and carrying a knife in a public place without reasonable cause.
Kathu Police Superintendent Col Chalermchai Hoersawat confirmed the suspect had been taken into custody for further legal proceedings.