World No. 1 Naomi Osaka reached the quarterfinals of the Western and Southern Open on Thursday, while fellow Japanese Yoshihito Nishioka beat Alex de Minaur of Australia in the men's draw to advance to the last eight of an ATP Masters 1000 event for the first time.

Osaka, a two-time major winner, beat world No. 30 Hsieh Su-wei of Taiwan 7-6(3), 5-7, 6-2 in the women's tournament.

The second-seeded Osaka fired 15 aces and broke Hsieh's serve five times to wrap the match in just under two and a half hours.

She will face seventh-seeded Elina Svitolina of Ukraine or Sofia Kenin of the United States for a spot in the semifinals.

Earlier in the day, world No. 77 Nishioka defeated world No. 38 de Minaur 7-5, 6-4.

The 23-year-old qualifier has won five matches in six days, including a victory over his injury-slowed countryman Kei Nishikori in the second round on Wednesday.

"I've always wanted to advance to the quarterfinals at a Masters tournament, so I am very happy," Nishioka said. "This is really a special moment for me."

In the quarterfinals, Nishioka will face world No. 19 David Goffin of Belgium, who knocked out France's Adrian Mannarino 7-6(6), 6-2 in third-round play.