MASON, Ohio (AP) — Ninth-seeded Venus Williams was knocked out of the Western & Southern Open by qualifier Ashleigh Barty in a three-set, second-round match on Wednesday.

Barty, who is ranked No. 48 on the WTA Tour, bounced back after dropping the second set to pull out a 6-3, 2-6, 6-2 upset of the 37-year-old Wimbledon finalist, who is ranked No. 9.

Earlier, 16th-seeded Madison Keys easily reached the women’s round of 16 in Cincinnati for the first time on her fourth try, needing just 50 minutes to zoom past Daria Kasatkina 6-2, 6-1. Keys, a right-hander who withdrew from last week’s Rogers Cup in Toronto with a left forearm injury, next will meet fourth-seeded Garbine Muguruza, the Wimbledon champion.

“I definitely thought I played really well,” Keys said. “I don’t know if I was the zone, press, but everything was going well. It was falling into place, and I didn’t have to rush anything.”

Keys was happiest about finishing quickly in the humid, 80-some-degree conditions.

“I definitely didn’t want to be out there a long time,” she said. “I wasn’t out there that long, but I was still drenched. I was happy to get back inside into the air conditioning.”

In men’s action, seventh-seeded Gregor Dimitrov defeated Feliciano Lopez 7-6 (5), 6-4 to reach the round of 16 in this U.S. Open warmup.

After being forced to a tiebreak in the first set, Dimitrov raised his level of play in the second with 13 winners to Lopez’s four. Dimitrov finished with 28 winners, twice as many as Lopez.

Also advancing to the third round were 11th-seeded Pablo Carreno Busta, 6-3, 7-6 (2) over Mischa Zverev; Juan Martin del Potro, 6-4, 6-4 over qualifier Mitchell Krueger; Karen Khachanov, 6-2, 6-2 over Thomas Fabbiano; David Ferrer, 6-4, 6-7 (5), 6-1 over Janko Tipsarevic; and Yuichi Sugita, 3-6, 7-6 (5), 6-1 over qualifier Joao Sousa.

Other seeded women reaching the third round were eighth-seeded Svetlana Kuznetsova, with a 6-3, 6-4 win over Yulia Putintseva, and Anastasija Sevastova, with a 6-2, 7-5 win over Roberta Vinci. Qualifier Camila Giorgi advanced with a 7-6 (1), 5-7, 6-3 win over Daria Gavrilova, and Carla Suarez Navarro moved on with a 6-2, 6-2 win over qualifier Aleksandra Krunic.