LOS ANGELES (AFP) - Seven-time Grand Slam champion Venus Williams will have to wait for a 50th career WTA title after bowing out in the third round of the claycourt tournament in Charleston, South Carolina, on Thursday.
Williams, the third seed, had put together back-to-back wins for the first time since lifting the trophy in Taiwan in February, but was toppled 7-6 (7/5), 2-6, 6-4 by Kazakhstan's Yulia Putintseva.
The 35-year-old American joined second-seeded Swiss Belinda Bencic, fourth-seeded Lucie Safarova and sixth-seeded Andrea Petkovic out of the tournament.
But top-seeded Angelique Kerber, the reigning Australian Open champion, powered into the quarter-finals with a 6-2, 6-3 victory over qualifier Kristina Kucova.
Kerber fired 35 winners and converted seven of her 10 break point chances, staying steady in difficult, windy conditions.
"It was a really tricky match," she said.
"It was really windy and it was a completely different condition than before. I played two days ago in the night session, and it was windy, cold.
"I'm really happy to win the match because she's a tough opponent who had great matches in Charleston. I'm happy to be back here."
Kerber said she was feeling at home on the green clay of Charleston, a good warm-up for the upcoming European claycourt season.
"Right now I'm feeling much better on clay again," she said. "Moving feels better. Also, when I hit the balls, I'm feeling the ball, I'm feeling the court."
In other early matches, Russian Elena Vesnina, who ousted Bencic in the second round, reached the quarter-finals with a 6-1, 6-3 victory over Spain's Lourdes Dominguez.
Vesnina next plays Germany's Laura Siegemund, who followed up her second-round win over eighth-seeded Madison Keys, with a 7-5, 6-2 victory over Croatia's Mirjana Lucic-Baroni.