Angelique Kerber of Germany celebrates during the women's singles match against Dominika Cibulkova of Slovakia at the WTA finals tennis tournament in Singapore, Oct. 23, 2016. Kerber won 2-1. (Xinhua/Then Chih Wey)
Angelique Kerber of Germany returns the ball during the women's singles match against Dominika Cibulkova of Slovakia at the WTA finals tennis tournament in Singapore, Oct. 23, 2016. Kerber won 2-1. (Xinhua/Then Chih Wey)
Angelique Kerber of Germany serves the ball during the women's singles match against Dominika Cibulkova of Slovakia at the WTA finals tennis tournament in Singapore, Oct. 23, 2016. Kerber won 2-1. (Xinhua/Then Chih Wey)
Dominika Cibulkova of Slovakia serves the ball during the women's singles match against Angelique Kerber of Germany at the WTA finals tennis tournament in Singapore, Oct. 23, 2016. (Xinhua/Then Chih Wey)
