Rapper/fight promoter Curtis "50 Cent" Jackson took a swipe at former UFC champion Ronda Rousey, who got knocked out on Saturday night by former boxing champion Holly Holm.

For the last year, Rousey and Floyd Mayweather Jr. have been taking verbal shots at each other. Several months ago, Rousey took things to the next level during a televised interview with ESPN - when she jabbed Mayweather over his controversial past regarding allegations of domestic abuse. She also questioned Mayweather's ability to read and felt she made more money, at least on a per second basis.

Rousey suffered her first defeat in Australia in the headline fight of UFC 193, when Holm dominated the entire fight with boxing ability and used well-known high kick to knock Rousey out cold in the second round.

Mayweather retired in September after a decision victory over Andre Berto. He is expected by most to return to the ring at some point in 2016.

50 Cent took to his Instagram account and posted an image, which he claimed was done under the request of Mayweather, who is close friends with the rapper.

"Floyd told me to post this… he want me to do the dirty work." - 50 Cent wrote to his millions of followers on social media.