Rafael Nadal's record 21st Grand Slam title, secured in an epic Australian Open final on Sunday was hailed by both Roger Federer and Novak Djokovic who had been tied with him on 20.
Nadal, 35, battled back from two sets down to defeat Russia's Daniil Medvedev 2-6, 6-7 (5/7), 6-4, 6-4, 7-5 in a gruelling 5hr 24min in Melbourne.
It crowned an extraordinary effort from Nadal at the year's opening major, having to modify his game to compensate for a degenerative bone disease in his left foot that ended his 2021 season last August.
Federer, who came close to becoming the first to 21 when he lost in five sets by Djokovic in the 2019 Wimbledon final, missed the Australian Open recovering from knee surgery.
"To my friend and great rival @rafaelnadal, heartfelt congratulations on becoming the first man to win 21 Grand Slam singles titles," 40-year-old Federer posted on Instagram.
"A few months ago we were joking about both being on crutches, amazing. Never underestimate a great champion. Your incredible work ethic, dedication and fighting spirit are an inspiration to me and countless others around the world."
Djokovic's hopes of being the first to 21 were dashed when he was deported from Australia prior to the Grand Slam over vaccination issues.
However, the 34-year-old Serbian tweeted his congratulations -- after he had first saluted Ashleigh Barty on her title win on Saturday.
"Amazing achievement. Always impressive fighting spirit that prevailed another time. Enhorabuena (Congratulations -- followed by applause, trophy and thumbs up icons)."