World No. 1 Carlos Alcaraz eased past Italy’s Matteo Arnaldi 6-3, 6-3, 6-4 to reach the U.S. Open quarterfinals on Monday in New York.

The Spanish 20-year-old joined Andre Agassi as the only men to reach three U.S. Open quarterfinals before the age of 21 in the Open Era (since 1968).

“The intensity from the start to the last ball, I think I played a really solid match,” Alcaraz said. “Less mistakes. I played my game. Tried to go to the net all the time. I am really happy with the performance and I am happy to be through.”

Alcaraz, the defending U.S. Open champion, had just two aces against Arnaldi’s four, and Arnaldi saved 7 of 12 break points. But Alcaraz won 38 of his 49 first-service points (77.6 percent) and 27 of 37 points at the net (73 percent).

Alcaraz had 31 winners to Arnaldi’s 22.

“Right now my favorite surface is hard court, and when I won Wimbledon I said I fell in love with grass,” Alcaraz said. “I am really comfortable with the three surfaces, but right now hard courts is my favorite one.”

In the quarters, Alcaraz will face either German No. 12 seed Alexander Zverev or Italian No. 6 seed Jannik Sinner, who were scheduled to face off later Monday.

No. 8 seed Andrey Rublev of Russia got past Great Britain’s Jack Draper 6-3, 3-6, 6-3, 6-4 to reach the quarterfinals.

Draper edged Rublev 18-14 in aces, but Rublev won an impressive 53 of 63 first-service points (84.1 percent). He overcame Draper saving 13 of his 17 break points and capitalized on Draper’s 36 unforced errors.

The other Round of 16 match scheduled for Monday pits Russian third seed Daniil Medvedev against No. 13 seed Alex de Minaur of Australia.

–Field Level Media