Rafael Nadal notes "historic triumph" by compatriot Carlos Alcaraz in Miami

WATCH: Alcaraz addressed the media after his maiden Masters 1000 victory in Miami.

Carlos Alcaraz earned his first Masters 1000 title at the Miami Open, and it came with a congratulatory message from Rafael Nadal on Sunday.

The Spanish legend applauded his young compatriot for his "historic triumph,” adding it was ''the first of many to come, for sure" in a post on social media.

The 18-year-old Alcaraz has already achieved something Nadal has not done in his own illustrious career—lifting the title in Miami. He's also the youngest to win an ATP Masters title since Nadal did in 2005 (Monte Carlo).

The pair played just two weeks ago in a semifinal at the BNP Paribas Open in Indian Wells, which finished in a tight three-set victory for the elder Spaniard. Following his win, Nadal spoke highly of Alcaraz’s all-around game.

"I think he has all the ingredients to become an amazing champion," said Nadal, who picked up a stress fracture injury during the contest that will sideline him for the next few weeks. "He can defend amazing balls. Of course, when he's playing aggressive, it’s difficult to stop him because his quality of the ball is very high.

"Looks like he's humble enough to work hard and to understand that we, the tennis players, if we want to be great champions, the only way is to keep improving during all our careers."

Nadal also had a congratulatory message for Miami finalist Casper Ruud, who trains at the Rafa Nadal Academy in Mallorca, noting his "amazing" tournament and a "great swing" through this stretch of the season. Ruud also won the title at Buenos Aires on clay a few weeks ago and will move up to a career-high ranking of No. 7.

Alcaraz will move up to a career-high No. 11 on Monday.