Alexander Zverev described Carlos Alcaraz as a future International Tennis Hall of Famer after losing to the Spaniard in a five-set classic in Sunday's French Open final.
Alcaraz clinched his third major title – and his first at Roland Garros – with a 6-3 2-6 5-7 6-1 6-2 success on Court Philippe-Chatrier.
The 21-year-old looked set for defeat when Zverev went 2-1 up, the German's aggressive style allowing him to dictate the contest from the baseline, but the Spaniard rediscovered his composure in the fourth set.
After evening things up, Alcaraz clinched two breaks in the decider to join compatriot Rafael Nadal on the list of French Open champions.
At the age of 21 years and 35 days, he is the youngest player in the Open Era to win men's singles titles at three different grand slams.
He has also needed the fewest major appearances (13) of any male player in the Open Era to capture grand slam titles on grass, clay and hard courts.
Speaking in his post-match interview, Zverev – who has lost both of his grand slam finals – said: "Congratulations Carlos. Third grand slam at 21 years old. It's incredible.
"You won three different ones. You're already a Hall of Famer and you're only 21 years old."
Alcaraz, meanwhile, thanked his support team for their work in helping him overcome a troublesome forearm injury that caused him to miss the Italian Open.
"My team have been incredible in the last month. We were struggling a lot with the injury. Coming back from Madrid, I didn't feel well," he said.
"I'm grateful to have the team that I have. I know everyone in my team is giving their heart to help me improve. I call this a team but it's a family.
"I have loved having part of my family here. I used to watch this tournament on TV and now I'm holding the trophy, so thank you very much.
"Everyone has a really important part in making this tournament special. It's not easy to do that, we complain a lot, but you all do a great job. Thank you to everyone.
"The crowd have been great since the first match until today. The support has been unbelievable in the matches and practice. I'll see you soon, for sure. Thank you."
Addressing Zverev, Alcaraz added: "It's unbelievable, the level you are playing at and the work you are putting in every day.
"I'm pretty sure you will win slams and this tournament very, very soon, so keep going and congratulations."