Roger Federer beats Robin Haase in the ABN AMRO World Tennis Tournament quarter-final last night to become the oldest ever world No 1 at the age of 36.
Federer’s triumph has attracted praise from a number of famous faces.
Andre Agassi, who formerly held the record, and Arsenal footballer Mesut Ozil both congratulated the veteran on his achievement.
The Swiss legend took to Instagram to post a photo of him celebrating, which was captioned: “A night to remember forever. Thank you to all my fans who have been there for me since the beginning.”
And Djokovic responded to the post, paying tribute to his rival.
“Incredible achievement @RogerFederer,” he commented on Federer’s post.
“Congratulations to the whole team and family @Ivanljubicic”
Djokovic has been unable to compete against his counterpart since picking up an elbow injury during Wimbledon last year.
The Serb is planning to return in the coming months after having surgery to fix the problem.
However, it is unclear when Federer will be able to clash with the former No 1.
The Swiss icon is preparing to undergo a lighter clay-court season in order to stay fresh for bigger events later this year.
Federer opted to play fewer tournaments in 2017 and that saw him claim his eighth Wimbledon title.