Conor McGregor unloaded vicious punches on a club patron in Ibiza this week ... with video showing the former UFC superstar striking a man twice during the violent altercation.
In a clip obtained by The Sun, Notorious appeared to be enjoying a night out with friends at Pacha around 5:53 AM on Tuesday ... when at one point, he leaned in and communicated with someone standing below him.
Whatever was said apparently didn't sit well with the 36-year-old fighter ... 'cause he went into MMA mode and attacked the guy with two clean left hooks.