HALLE WESTFALEN: (APP) Teenage German Alexander Zverev caused a major shock on Saturday as he beat eight-time winner Roger Federer in the Halle grass court semi-finals.Zverev, 19, triumphed 7-6 (7/4), 5-7, 6-3 to reach only his second ATP Tour final after being beaten by Austria's Dominic Thiem on ...