Five division world champion Floyd Mayweather Jr. lashed out at UFC superstar Conor McGregor, who on Saturday night in Abu Dhabi was knocked out in two rounds by Dustin Poirier.

McGregor made his pro debut in boxing back in August of 2017, against a comebacking Mayweather, who snapped a two-year retirement to take the fight.

Mayweather broke down and stopped McGregor in the tenth round. After the fight, Mayweather retired from the sport for good.

In the last few years, McGregor made several attempts to secure a rematch with Mayweather.

Once he realized Mayweather would never face him again, McGregor turned his attention to a boxing match with current WBA welterweight champion Manny Pacquiao.

Mayweather outboxed Pacquiao for a twelve round unanimous decision in May of 2015 - in what is still the most lucrative pay-per-view event in history.

There were ongoing discussions to make Pacquiao-McGregor in 2021. Both athletes are handled by the same management company.

After suffering his recent knockout loss, a future fight with Pacquiao is likely a dead scenario.

Mayweather still believes McGregor copied his persona and never received the criticism that came along with it.

"The world knows Con Artist McLoser can steal everything from me and be loved but I’m hated. That just lets you all know that racism still exists. Just know, that bum will never be me or be on my level. I’m just built different, my mindset is on another planet, my skills are second to none, I’m a natural born winner and yes I talk a lot of trash, but every time I back it up! This is what they hate," Mayweather stated on social media.

"It’s sad that you can be a poor black kid from the ghetto that has dealt with racism your whole life and work extremely hard to put yourself and your family in a better position, and most of the hate come from my own people. Conor can not even win in his own sport, but talking about coming back to boxing to fight Pacquiao. Nobody wants to see that, it's like my leftovers eating leftovers."