She raced to a 3-0 lead in the first set and then 4-0 in the second against the shaky Tsurenko, who finished with more unforced errors than points in her first major quarterfinal.
Osaka, who was born in Japan but moved to the U.S. at age 3,
Born in Japan, to a Haitian father and Japanese mother, she moved to the U.S. as a 3-year-old. She holds dual citizenship, living for a time in New York and now in South Florida while representing Japan in Fed Cup. She was followed on Arthur Ashe Stadium by Kei Nishikori facing Marin Cilic in a men’s quarterfinal.
Together, Osaka and Nishikori were the first Japanese woman and man to make the quarterfinals of the same Grand Slam since Date and Shuzo Matsuoka at Wimbledon in 1995.
The 20-year-old said she was nervous, claiming to be “freaking out inside” — though it certainly never showed.
“Just like my entire body was shaking, so I’m really glad I was able to play well today,” she said.
She won 59 points to just 28 for the unseeded Ukrainian, who knocked off No. 2 seed Caroline Wozniacki in the second round.
But after laboring through the heat in her previous match, Tsurenko said she was sick Wednesday, waking up with a sore throat and not breathing well.
“Unfortunately during this tournament I had many issues with my health, and today was not my day obviously. I was not feeling well,” she said.
Osaka had consecutive 50-minute matches earlier in the tournament, including a 6-0, 6-0 thrashing of Aliaksandra Sasnovich in the third round.
She was finally tested in the round of 16, edging past No. 26 Aryna Sabalenka 6-3, 2-6, 6-4 in a little more than 2 hours, but she was back in complete control against Tsurenko, winning 20 of 22 points (91 percent) on her first serve.
Tsurenko labored in the heat during her fourth-round victory over Marketa Vondrousova, having her temperature and blood checked during a medical timeout in the first set and nearly quitting when she trailed early in the second. She recovered to win in three sets, with her opponent accusing her of acting after the match.
Tsurenko didn’t appear bothered by the conditions, but whether it was her health or just first-time jitters, she was off from the minute she stepped onto Arthur Ashe Stadium.
She pushed some balls a few feet past the baseline, often failing to make Osaka do anything special to win a point and finishing with 31 unforced errors.
“I hate matches like this,” Tsurenko said. “I didn’t want to show this kind of game in front of this big crowd, but unfortunately I’m just not able to play now.”
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