Top-seeded Jessica Pegula saved four match points in a third-set tiebreaker and beat Victoria Azarenka 6-4, 3-6, 7-6 (7) Friday to reach the Charleston Open semifinals. Danielle Collins, the Miami Open champion, won her 11th straight match with a 6-3, 6-4 victory over Elise Mertens. Pegula squandered four match points of her own, up 5-4 in the final set against Azarenka, a two-time Australian Open champion. But tied 7-7 in the tiebreaker, Azarenka missed wide with Pegula at the net, then pushed a service return long. “I was playing well today, but you know what? Stuff happens and you’ve got to figure it out,” Pegula said. “And I was able to figure it today and I’m just going to use that feeling, that confidence.”