Roger Federer is proud to play in an era of tennis which he labelled as "special" after Novak Djokovic clinched his 20th grand slam title.

Djokovic beat Matteo Berrettini 6-7 (4-7) 6-4 6-4 6-3 at Wimbledon on Sunday to seal his third major trophy of the season.

It is the world number one's sixth title at the All England Club, as he defended the crown he won in an epic final against Federer in 2019.

Djokovic is now level in the record books with Nadal and Federer, with all three of the greats on 20 grand slams each.

The Serbian will look to make that 21 at Flushing Meadows later this year, as he aims to become just the second player in the Open Era to complete a clean sweep of the men's slams in a single year, after Rod Laver in 1969.

In the post-match presentation, Djokovic hailed Nadal and Federer as inspirations, and the latter echoed that sentiment.

"Congrats Novak on your 20th major," Federer, now ranked eighth in the world, tweeted.

"I'm proud to have the opportunity to play in a special era of tennis champions. Wonderful performance, well done!"