He wrote: "The girls in the bar I was in all night waved goodbye to two elderly customers and their son ...
"My wife and I followed only seconds after them.
"Within 20/30 meters of leaving the bar the Thais were punching the 65-year-old old lady in the face."
"The elderly gentleman was down on the floor, and their son was beaten very badly."
"At this point I caught up to the scene and pushed one of the youths away from the woman," he continued.
"I got severely punched and kicked for my troubles, but felt the need to protect this frail lady.
"The three of them are still hospitalised, and I will need cosmetic dental work done."
Another person quoted in British media, who claims to have witnessed the assault, posted on a separate forum claiming they overheard a group of Thai men saying they were going to attack "farangs" - a derogatory term for Europeans.
They posted: "It happened last night at 2am when a group of Thai men who were overheard saying they were there to attack "Farangs", attacked an elderly couple leaving a bar.
"A good Samaritan who stopped the beating of one of the victims, a 65-year-old woman, was also beaten. It is believed the men were gang members."
Local police have released the CCTV footage to help find the attackers.
Two of the attackers are reportedly in custody but two more are still at large.
The condition of the three victims is not known.
- news.com.au