Tennis

FLUSHING MEADOWS, N.Y. — Naomi Osaka is going deep again.

Osaka, the four-time Grand Slam champion who has been in something of a tennis wilderness the past three years, is back in the U.S. Open semifinals. She beat No. 11 seed Karolína Muchová 6-4, 7-6(3) in a pulsating match, which riveted even as Muchová played essentially on one leg.

The match was the latest exclamation point for Osaka’s long and short journey back to the biggest matches on the brightest stages. It began nearly two years ago, but went from 35 miles per hour to 90 only in the past month.

“I learned I loved tennis way more than I thought I did, and I learned that, you know, I actually really love challenges,” said Osaka in her news conference, who earlier this year questioned how long she would keep at the comeback without getting the results she wanted.