The Rak-Su singer was punched and elbowed in the head "several times" by a group of nine men at the hotspot Sheesh in Chigwell for no apparent reason.
An eye witness told The Sun newspaper's TV column: "It blew up in a couple of seconds.
"Myles seemed to have sat down with his friends in an area where these other guys seemed to think they had already reserved.
"Rather than talk about it quietly, they went straight in for a fight.
"A few seconds later Myles had been whacked several times in the face and body and his friends had stepped in to try and help protect him too, but they were massively outnumbered.
"It was awful to watch and a ridiculous overreaction given what had happened.
"Security quickly intervened and had to manhandle the gang out of the bar before somebody got seriously hurt, and then kept Myles' group inside because they were kicking off outside. Glass bottles were being smashed and some cars were damaged too -- people were calling for the police."
It's not known whether the 28-year-old singer - who was left shaken up by the incident - has been left with any bruises or marks as a result of the attack.
A source said: "Nobody could understand what had started it or whether they targeted Myles deliberately."
Meanwhile, although he's only just left the 'I'm A Celebrity... Get Me Out of Here!' jungle and has television and music work lined up for most of this year, Myles has still found time to join the dating app Raya in the hope of finding love in 2020.
He said recently: "Don't say any names. But here we go. This is basically Raya. That's all the people I've matched with."
