The top two seeds, Australia's Ashleigh Barty and Romania's Simona Halep, respectively, scored quarterfinal victories Friday and moved on to the semifinal round at the Porsche Tennis Grand Prix in Stuttgart, Germany. Fourth seed Elina Svitolina of Ukraine joined them, advancing past seventh-seeded Petra Kvitova of the Czech Republic 6-7 (4), 7-5, 6-2. Svitolina needed two hours, 37 minutes to win the match, saving 13 of 16 break points (81.3 percent). The No. 5 seed Aryna Sabalenka of Belarus will meet Halep after