Germany’s Angelique Kerber makes a backhand return to United States’ Coco Vandeweghe during their fourth round match at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 22, 2017. Germany’s Angelique Kerber makes a backhand return to United States’ Coco Vandeweghe during their fourth round match at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 22, 2017.