- Wimbledon champion Petra Kvitova and finalist Eugenie Bouchard both crashed out of the second round of the Cincinnati hardcourt tournament in a setback to their US Open preparations.
Ukrainian teenager Elina Svitolina toppled third-seeded Czech Kvitova 6-2, 7-6 (7/2). Bouchard went down to Russian veteran Svetlana Kuznetsova 6-4, 3-6, 6-2.
Bouchard also lost her opening match at her home tournament in Montreal last week.
Kvitova suffered a third-round exit in Montreal.
"I can still find moments when I really don't know what's happening out there," admitted Kvitova. "Even if I'm older and have more experience, I can still have days like today."
Top seed Serena Williams got through safely as she defeated Australian Samantha Stosur for the second time in as many weeks, 7-6 (9-7), 7-6 (9-7).