Ivanovic breezes into semis

​Ana Ivanovic continued to ease her way through the draw at the Aegon Classic on another day of upsets in Birmingham.

The top seed has looked at home on the grass and saw off Czech Klara Koukalova without too much difficulty, 6-1 6-4 to reach the semi-finals.

The Serbian said on "I really tried to do my thing because I know she can be dangerous and last time we played, in Doha, I lost.

"She's won on grass in the past and is a great competitor, as she showed in her matches this week. I'm serving well, which I'm happy about. Each match is a new challenge and I'm happy I'm improving with each one."

In the last four Ivanovic will play China's Zhang Shuai, who knocked out third seed Sloane Stephens 6-3 6-1.

Casey Dellacqua ended the run of 43-year-old Kimiko Date-Krumm, who was playing in the quarter-finals at Edgbaston for the first time since 1989.

Date-Krumm knocked out defending champion Daniela Hantuchova in round three but was no match for Dellacqua, who won 6-1 6-0.

In the semi-finals the Australian will play Czech Barbora Zahlavova Strycova, who upset fourth seed Kirsten Flipkens 6-4 6-2.