Rafael Nadal said Novak Djokovic had helped push him beyond his limits for 15 years after losing one final clash with the Serbian at the 6 Kings Slam in Saudi Arabia.
Djokovic and Nadal met in the third-place play-off at the inaugural event in Riyadh, having lost their respective semi-finals against Jannik Sinner and Carlos Alcaraz on Friday.
Nadal, who will hang up his racket after the Davis Cup Finals next month, was beaten 6-2 7-6 (7-5) by his great rival in his final match at an individual event.
The duo – who made up two-thirds of tennis' 'Big Three' alongside Roger Federer – have won 46 grand slam singles titles between them and met in 60 ATP Tour-recognised matches, with Djokovic winning 31 to Nadal's 29.
Djokovic is also the only player to ever defeat Nadal at all four grand slams.
Speaking after Saturday's match, an emotional Nadal thanked Djokovic for the role he played in his glittering career, saying: "Novak, you helped me go over my limits for 15 years.
"I would probably not be the player I am without you. I wish you the best of luck for the future."
When asked what he will miss most after his retirement, Nadal added: "Almost everything.
"It has been a dream come true to be able to play for almost 20 years, being competitive, having the chance to play in the best places in the world, which I watched on TV as a kid.
"I cannot thank you enough for the support and love I have received all around. It was an amazing journey at every single tournament over the years. I feel very fortunate to be a tennis player."
Djokovic, who also defeated Nadal at the Paris Olympic Games at the Spaniard's favoured Roland-Garros venue in July, then outlined his hope that his rival will not turn his back on the sport entirely.
"I don't know where to start with Rafa," Djokovic said. "An amazing career. I could speak all night. It has been an honour to share the court with you.
"I go back to the very first match we played and who would know we would be standing here almost 20 years later, playing 60 times. I have the utmost respect for you. Incredible athlete, incredible person.
"The rivalry has been incredible, very intense, so I hope we will have the chance to sit on the bench somewhere, have a drink and reflect.
"I know how much sacrifice there has been. It is an emotional day, so don't leave tennis, man! Stay with us! You have left an amazing legacy."
Nadal will be part of the Spain team that faces the Netherlands in the Davis Cup Final 8 on November 19, with a semi-final matchup against Germany or Canada on the line.