Jabeur looked comfortable on clay for this season, not dropping a set in three matches CHARLESTON, S.C.: Second-seeded Ons Jabeur led the top seeds into the semifinals at the Charleston Open on Friday. No. 3 seed Daria Kasatkina and No. 4 seed Belinda Bencic, the defending champion, also advanced to the last four with quarterfinal victories at the season’s first clay-court tournament. Jabeur, who fell to Bencic in the championship match here a year ago, lost one game in beating Anna Kalinskaya, who retired with an illness while trailing 6-0, 4-1. Kasatkina dropped the first set to past champion and ninth-seeded Madison Keys before rallying for a 6-7 (5), 6-4, 6-2 victory. Bencic won her ninth straight match on the green clay of the Credit One Tennis Center, defeating seventh-seeded Ekatarina Alexandrova 6-3, 6-3. Top-seeded Jessica Pegula faced 12th-seeded Paula Badosa for the chance to end Bencic’s win streak. Jabeur looked comfortable on clay for this season. She has not dropped a set in three matches. She’ll try and keep that going in the semis against Kasatkina, who lost her first set of the week to Keys. “I was feeling good on the practice. I was training well with my team,” she said. “Playing matches is always different. And I felt like, ‘OK, I’m just going to focus on each match and see what’s going to happen.’” Jabeur, ranked fifth in the world, had four aces and no double faults. She won nearly 78 percent of her first serves and saved all three break point opportunities Kalinskaya had. The only thing that might slow her down? The weather forecast for Saturday, which calls for steady rain throughout. “I’m going to call my people in Tunisia and bring the sun here,” she joked. Keys was two games away from advancing, up a set and 4-3 in the second when Kasatkina found her game to win nine of the last 11 games. Kasatkina hadn’t won more than one match in her past six tournaments, including a first-round exit last time out at the Miami Open. Now, she’s a win away from a WTA final. “The beginning of the year was a bit rough,” Kasatkina said. “Just so happy to finally be on the right track.”