– As the U.S. Open swings into its final days, Japan, a relative outsider, has emerged at the fore. Known more by its passion for baseball and sumo wrestling than for producing elite tennis players, the country has its two best players blazing a trail at Flushing Meadows.

Naomi Osaka, an endearing 20-year-old, joined Kei Nishikori, a finalist at the 2014 U.S. Open, in the semifinals, giving Japan two players in the final foursomes of a Grand Slam event for the first time.

Osaka, the No. 20 seed, rolled past unseeded Lesia Tsurenko of Ukraine 6-1, 6-1 in just 57 minutes in Arthur Ashe Stadium on Wednesday to reach her first Grand Slam semifinal. The No. 21-seeded Nishikori followed her on the same court, but took four times as long to prevail, overcoming a shaky first set to upset No. 7 Marin Cilic of Croatia 2-6, 6-4, 7-6 (5), 4-6, 6-4 in a rematch of their 2014 final.

Cilic needed less than two hours to win that final in straight sets. It took the 28-year-old Nishikori 4 hours, 8 minutes to avenge the loss and reach the U.S. Open semifinals for the third time.

Osaka became the first woman from Japan to reach a semifinal at the U.S. Open, and the first to reach that stage of any major tournament since Kimiko Date did so at Wimbledon in 1996.

Osaka and Nishikori already had become the first duo from Japan to reach the quarterfinal stage of the same Grand Slam event since Wimbledon in 1995, when Shuzo Matsuoka and Date reached the final eight of their respective draws. Both Matsuoka and Date were in attendance Wednesday, working as broadcasters for Japanese television networks.

Osaka said her muted celebration belied an inner anxiety.

"I was freaking out inside," she said in a courtside interview and added, "My entire body was shaking, so I'm really glad I was able to play well today."

New York Times