Roger Federer saw Rafael Nadal equal his all-time record of 20 Grand Slam titles with a 13th French Open victory on Sunday and hailed it as "one of sport's greatest achievements".
Nadal demolished Novak Djokovic 6-0, 6-2, 7-5 to add a 13th Roland Garros to his four US Opens, two Wimbledons and one Australian Open crown.
"I have always had the utmost respect for my friend Rafa as a person and a champion," tweeted Federer, who sat out the tournament to recover from knee surgery.
"As my greatest rival over many years, I believe we have pushed each other to become better players.
"Therefore it is a true honour for me to congratulate him on his 20th Grand Slam victory.
"It is especially amazing that he has won Roland Garros an incredible 13 times which is one of the greatest achievements in sport.
"I hope the 20 is just another step on the continuing journey for both of us."