Roger Federer shared a touching, classy tribute to his greatest rival Rafael Nadal after his sensational Australian Open triumph

• Rafael Nadal won his 21st Grand Slam title on Sunday as he clinched the Australian Open.
• Roger Federer was quick to congratulate his "friend and great rival."

Roger Federer posted a classy statement congratulating his great friend and rival Rafael Nadal on his sensational Australian Open triumph, describing the Spaniard as an "inspiration."

Nadal came from two sets down to beat Daniil Medvedev 2-6, 6-7 (5-7), 6-4, 6-4, 7-5 in the final of the men's singles on Sunday.

In doing so, he clinched his 21st career Grand Slam title to move one clear of both Federer and Novak Djokovic in the all-time leaderboard.

"To my friend and great rival Rafael Nadal, heartfelt congratulations on becoming the first man to win 21 Grand Slam singles titles," Federer wrote to Nadal in an Instagram story shortly after his victory.

"A few months ago we were joking about both being on crutches. Amazing. Never underestimate a great champion."

Nadal cut his 2021 season short due to a long-term left foot injury which saw him needing crutches to help him walk.

"Your incredible work ethic, dedication and fighting spirit are an inspiration to me and countless others around the world," Federer continued. "I am proud to share this era with you and honoured to play a role in pushing you to achieve more - as you have done for me for the past 18 years.

"I am sure you have more achievements ahead but, for now, enjoy this one!"

Djokovic also took to social media to congratulate Nadal on his win.

"Congratulations to Rafael Nadal for 21st Grand Slam. Amazing achievement. Always impressive fighting spirit that prevailed another time," tweeted the Serbian. World number one Djokovic was unable to defend his title this year after being deported from Australia following a dispute over a medical exemption relating to him being unvaccinated.

Djokovic also congratulated Medvedev for coming second, as well as the women's singles winner Ashleigh Barty, who beat American Danielle Collins in Saturday's final to claim her first ever Australian Open title.

"[Medvedev] gave it his all out there and played with the passion and determination we have come to expect from him," added the 34-year-old. "There has been some outstanding tennis played at this year's [Australian Open] and the finals were exceptional.

"Congratulations to @ashbarty for an amazing performance in front of her home crowd and to Danielle Collins for an incredible tournament."

Addressing Melbourne's Government House for the traditional morning-after photocall on Monday, Nadal spoke of the mutual respect between himself, Federer, and Djokovic, who together have dominated men's tennis for the last decade-and-a-half.

"We are always very respectful of each other," he said. "I think we treat this rivalry in a positive way throughout our careers. I received plenty of messages. I am sorry I have not been able yet to reply to every one, you can imagine. But I really feel very proud about the way that we managed our rivalry during all our careers.

"At the end of the day it's just a game and in some way we achieved more than what we ever dreamed when we were kids.

"So at the end, it's not the fact that one has 21, and the others have 20. Or one has 23 and the others have 21. We did, I think, great things for our sport, and we achieved our dreams. And I feel lucky to be part of this era, that has been very special."