Wuhan Open: Zheng Qinwen faces Leylah Fernandez after Wang Xinyu beat US Open finalist

Coco Gauff moved into the quarterfinals of the Wuhan Open on Thursday with a 6-4, 6-1 win over 17th-ranked Marta Kostyuk in just over an hour.

It was the fourth-seeded Gauff's eighth straight victory in the WTA Tour's Asian Swing after the American won the China Open last week, a victory that moved her back into the top five of the rankings.

Gauff fired two aces and broke the Ukrainian's serve five times – losing a serve of her own – as she won a one-sided match and extended her lead in her head-to-head series to 3-1.

“I’m really happy with my performance today,” said Gauff. “It was a pretty straightforward game. Marta and I always have a few good fights. Today I was able to win in straight sets.”

Gauff will be the only American left in the draw after third-seeded Jessica Pegula and Tour rookie Hailey Baptiste both lost.

Pegula, the US Open finalist, had a tough afternoon against China's 51st-ranked Wang

Wang had won their only previous second-round meeting at Wimbledon in three sets earlier this year and got off to a fast start here, beating Pegula twice in the opening set to take the lead.