It’s women’s quarterfinal day Thursday at Wuhan with 6 of the Top 16 in action.

Angelique Kerber made a winning debut as a No. 1 player.

Angelique Kerber make her debut as a World No. 1 this week in Wuhan.

The Top 8 seeds receive opening-round byes in Wuhan, so Kerber will start against either American CoCo Vandeweghe or France’s Kristina Mladenovic. From there her difficult path will likely see No. 14 and Slam winner Petra Kvitova, then No. 7 Carla Suarez Navarro or No. 11 Johanna Konta, then likely No. 4 Simona Halep or No. 8 Madison Keys in the semifinals.

Kerber had wrapped-up the No. 1 ranking when Serena Williams lost in the semifinals, and then went 2-0 as the yet-unofficial No. 1 by winning her semifinal match and the final. The new WTA rankings will be released on Monday with Kerber in the top spot.

The women’s final will get underway in a few minutes.

Angelique Kerber became the new WTA No. 1 Thursday night at the US Open.

“I think the key of the match was the first set,” said Kerber, broken three times in the first set, and breaking it down for any media members that couldn’t read the scoreline. “I think in the second set, what I did good [was] that I played the first few games really tough so that I was up 3-0 very fast. Then I could continue my good play, yeah, in the next few games.”

In the quarters Serena will face a familiar nemesis, No. 5 seed Simona Halep, who worked past Spain’s Carla Suarez Navarro, 6-2, 7-5.

“It’s been a good week,” said Wozniacki, who covered the court like her days at the No. 1 ranking. “I’m really happy about the way I played. Obviously Madison is a strong player. She hits the ball really hard. But I managed to really play well, get a lot of returns in. I served well, which I was pleased with.”

“You never gave up on me and really helped me get through,” the 21-year-old Keys told the Arthur Ashe Stadium crowd.

“So far, so good,” Serena said regarding the shoulder injury that had her exit early from the Rio Olympics.

“I was shaking a little bit,” said Sevastova after ousting the French Open champ Muguruza. The Latvian came back to tennis after quitting the game from 2013-14 with back injuries.

Serena and Venus return to the US Open Tuesday.

Former champions Novak Djokovic and Rafael Nadal headline opening at the US Open Monday.