Naomi Osaka Simply Doesn’t Lose When She Gets to Grand Slam Quarterfinals

Naomi Osaka of Japan returns a shot against Coco Gauff of the United States during the fourth round of the U.S. Open tennis championships in New York on Sept. 1, 2025. Kirsty Wigglesworth/AP Photo

NEW YORK—Once Naomi Osaka is in the quarterfinals of a Grand Slam tournament, look out.

For a while, it was getting there that was the problem.