Police identified the victim as Ruslan Uma, 18. According to a police report filed with Pol Lt Wisanu Chumee of the Patong Police, the assault took place at around 6:18am.
Mr Ruslan told police that a foreign man entered the mall area and began urinating.
When Mr Ruslan attempted to intervene and stop the man, the tourist punched him twice in the face, then flung him to the ground and continued his attack.
A second foreign man then joined in the assault, attacking one man who tried to stop the attack on Mr Ruslan.
More bystanders then intervened and both foreigners fled.
CCTV footage was submitted to police as part of the report. Officers advised Mr Ruslan to undergo a medical examination due to concerns over a possible head injury. He was later admitted to Patong Hospital, where he is recovering.
On Saturday afternoon, reporters visited Mr Ruslan at the hospital, where he was described as drowsy and receiving intravenous antibiotics and fluids. Medical staff have reportedly withheld food and water pending further tests. His condition remains under observation.
Mr Ruslan’s sister, who asked not to be fully identified, told reporters that doctors had detected a blood clot in his brain and were awaiting further X-rays to determine the extent of the injury.
“We want the police to act quickly. He was badly beaten and has never experienced anything like this before,” she said. “He’s worked at that mall for eight months without any trouble until now. I want the attacker to be prosecuted to the fullest extent of the law.”
Patong Police confirmed that an investigation was underway.