SaturdayAt Porsche-ArenaStuttgart, GermanyPurse: $731,000 (Premier)Surface: Clay-IndoorSinglesSemifinalsCaroline Wozniacki (4), Denmark, def. Simona Halep (2), Romania, 7-5, 5-7, 6-2. Angelique Kerber, Germany, def. Madison Brengle, United States, 6-3, 6-1. DoublesSemifinalsBethanie Mattek-Sands, United States, and Lucie Safarova (3), Czech Republic, def. Petra Martic, Croatia, and Stephanie Vogt, Liechtenstein, 4-6, 6-3, 10-0. Caroline Garcia, France, and Katarina Srebotnik (2), Slovenia, def.