Fifth seed Li Na from China beat German Angelique Kerber 6-4, 6-4 in a pre-quarters match of the Western and Southern Open tennis tournament and automatically moved to the last four due to the retirement of Agnieszka Radwanska.
Li, the defending champion, would face the winner of the Serena Williams-Simona Halep match in the semifinals, reports Xinhua.
Radwanska announced her withdrawal after beating Elena Vesnina 6-0, 6-2 because she needed to attend the funeral of her grandfather Saturday.
