Aug. 26 (UPI) -- Carlos Alcaraz said he "couldn't get a rhythm," but still managed to oust American Reilly Opelka in straight sets in his first match of the 2025 U.S. Open.

The second-ranked Spaniard broke his No. 67 foe three times and totaled just 17 unforced errors, compared to Opelka's 32, in the 6-4, 7-5, 6-4 match Monday in Flushing, N.Y.

"I couldn't get the rhythm that I wanted to get in the match, but I'm just really happy with everything I've done," Alcaraz said on the ESPN broadcast. "I think the return was one of the best things I did, and then I just tried to play my best tennis, tried to be focused on my serve.

"Overall, I think I had a really great performance."

Alcaraz will take on No. 65 Mattia Bellucci of Italy in the second round. Bellucci beat No. 111 Juncheng Shang of China in his first-round match. The winner of the Alcaraz-Bellucci meeting will battle No. 34 Luciano Darderi of Italy or No. 127 Eliot Spizzirri of the United States in the third round.