Police were called to the scene, a residence in Soi Namtok Kathu, at about 5:20am.
Police arrived at the scene to find 22-year-old Anukun Ketkaew lying unconscious in a pool of blood, with stab wounds to his chest and ribs.
Rescue workers from the Phuket Kusoldharm Foundation and a medical team in an ambulance from Bangkok Hospital Siriroj provided immediate first aid and rushed Mr Anukun to Vachira Phuket Hospital, where he was pronounced dead from his injuries.
The assailant was identified as 21-year-old Patipat Chokamnuay.
According to witnesses, Patipat, driven by jealousy, attacked Mr Anukun after discovering that his ex-girlfriend, ‘Ms Sai’, had started a new relationship.
Ms Sai, who was present at the scene, told police that she had broken up with Patipat only a few days ago and had been seeing a new man for a few days, which had made Patipat jealous.
Following the attack, Patipat fled the scene but later turned himself in at Kathu Police Station.
Police said they had documented the incident and are proceeding with legal action against the suspect.