World No.7 Alexander Zverev has cruised through to the second round of the Mexican Open with a 6-3 6-1 win over Spanish teenager Carlos Alcaraz.
But the German was full of praise for Alcaraz after the match, comparing him to Rafael Nadal and saying he is destined for the top 10.
"He is 17 years old and everyone is looking at him right now," Zverev said of his opponent.
"My guess is he will be top 10 by 2024, in three years' time when he is 20.
"He is definitely going to have a long and great career and it won't be the last time I play him."
Zverev said Alcaraz moves well and hits the ball with a heaviness that was unusual for a player so young.
"His shots are extremely heavy, his forehand particularly," said Zverev.
"He reminds me of Nadal ... the heaviness of the ball is very similar. He will only improve from now on."
At the Australian Open last month, Alcaraz became became the youngest player to win a grand slam match since Thanasi Kokkinakis in 2014.
Zverev will next meet Serbia's Laslo Djere at the Abierto Mexicano Telcel on Thursday.
In other results, Canadian world No.18 Felix Auger Aliassime fought out an epic second-set tie-break to defeat Tennys Sandgren 6-3 7-6 (10).
And 20-year-old American Sebastian Korda downed veteran Marin Cilic 7-5 6-2.