Cristiano Ronaldo has achieved it all during his illustrious football career and the three-time Ballon d'Or winner is seemingly eyeing a new challenge.

After captaining Portugal to their first major title at Euro 2016 following Real Madrid's Champions League triumph, Ronaldo stepped into the Octagon with UFC star Conor McGregor on Sunday.

Enjoying a break from football duties in the United States, a tanned Ronaldo joined the UFC featherweight champion at his Las Vegas training camp.

Ronaldo took to Instagram to share a photo of the pair's dramatic stair-down pose, writing: "Great to see u bro!!".

Preparing for a welterweight rematch against Nate Diaz at UFC 202 next month, McGregor uploaded a picture of his own with the star-studded duo together in the ring.

The Irishman wrote a caption, which read: "My brother Ronaldo dropped by the gym today! He is an animal. Thank you @cristiano, much respect! I will see you for that Forbes number one spot next year. #ThisIsTheMacLife."