(Reuters) - Top seed Ana Ivanovic breezed into the quarter-finals of the Aegon Classic in Birmingham, England with a 6-1 6-1 victory over American Lauren Davis on Thursday but second seed Samantha Stosur was knocked out.
Ivanovic was joined in the quarter-finals by third seed Sloane Stephens and number four Kirsten Flipkens, who beat American Alison Riske 7-6 (4) 2-6 6-1 and Canadian Aleksandra Wozniak 1-6 7-5 6-4 respectively, but defending champion Daniela Hantuchova lost.
In the first game Serb Ivanovic trailed 0-40 on serve but that proved to a minor blip as the former French Open winner unleashed 28 winners in a dominant display.
"I just felt the ball really good, I timed it well," the 26-year-old told reporters. "I knew she's a player who stays low in the grass and it can work well sometimes so I really tried to stretch her and come forward."
Ivanovic's main rival at the grasscourt event was expected to be Stosur but the 2009 U.S. Open champion went down 2-6 6-2 6-2 against fellow Australian Casey Dellacqua.
Dellacqua next meets 43-year-old Japanese Kimiko Date-Krumm who proved age is just a number as she beat seventh seed Hantuchova 6-4 6-0.
"She was hitting lines, moving well, coming to the net, serving unbelievably well," Hantuchova said. "I thought I was always going to have chances on her serve but today just everything went her way".
(Reporting by Tom Hayward, editing by Tony Jimenez)