Khabib Nurmagomedov has challenged Floyd Mayweather to a showdown, telling his fellow undefeated fighter: “In the jungle there is only one king”.

Nurmagomedov extended his perfect professional mixed martial arts record to 27-0 and retained his UFC lightweight title with a stunning fourth-round submission victory over Conor McGregor in Las Vegas last weekend.

McGregor made a brief foray into boxing last year to take on Mayweather, who moved to 50-0 in the paid ranks by stopping the Irishman in the 10th round of their highly lucrative showdown.

Former multi-weight champion Mayweather was unable to knock McGregor down, which Nurmagomedov did over the course of last Saturday’s bout at the T-Mobile Arena before forcing his bitter rival to tap out.

And in a video posted on Instagram by Mayweather CEO Leonard Ellerbe, Nurmagomedov said: “Let’s go Floyd. We have to fight now: 50-0 versus 27-0.

“We are two guys who never lose. (But) in the jungle there is only one king. Of course, I am the king because he cannot drop McGregor but I drop him easily. Let’s go.”

Khabib and Ellerbe were both ringside in Russia for the World Boxing Super Series event, where Mayweather promoted cruiserweight Andrew Tabiti advanced in the cruiserweight portion of the tournament with a win over Russia's undefeated Ruslan Fayfer.

Mayweather has not fought since overcoming McGregor but stated last month that he was coming out of retirement for a rematch with Manny Pacquiao.

Nurmagomedov, meanwhile, is in the spotlight for his role in the ugly post-fight melee which followed his win over the Dubliner at UFC 229.

The Russian had his purse withheld by the Nevada State Athletic Commission, which sanctioned the event, after leaping over the cage and attacking a member of McGregor’s team.

Both Nurmagomedov and McGregor have been given temporary suspensions by the NSAC, pending a full investigation.