Angelique Kerber will be new world No. 1
                                
                                
                                    (Newser) -
                                    Serena Williams was upset in the US Open semifinals for the second year in a row, beaten 6-2, 7-6 (5) by 10th-seeded Karolina Pliskova of the Czech Republic on Thursday night. Williams, who clutched at her left leg between points in the second set, double-faulted to end it. Afterward, her...