Top-ranked Serena Williams gave her family a second victory Friday at the Family Circle Cup, halfway to what she and sister Venus need to set up their first showdown in four years.
Serena Williams defeated American Mallory Burdette, 6-4, 6-2, a short time after Venus outlasted Varvara Lepchenko 6-2, 4-6, 6-2. Each Williams sister must win a quarterfinal contest later Friday for their own meeting on Saturday.
Serena earned her 12th straight victory at the Family Circle, following titles in her last two appearances here in 2008 and 2012.
Serena and Venus had their third-round matches postponed Thursday because of a 7 1-2 hour rain delay.
The sisters have not played against one another since 2009 at the Sony Ericsson Championships. Serena holds a 13-10 lead on Venus, although the two have only played twice on clay with each claiming a victory.
Venus faces 18-year-old American Madison Keys, a straight sets winner over Bethanie Mattek-Sands, in the quarterfinals. Serena will play sixth-seeded Lucie Safarova later Friday. Safarova, the Family Circle runner-up to Serena last year, ousted No. 11 seed Sorana Cirstea, 6-3, 5-7, 6-1.
No. 2 seed Caroline Wozniacki plays Stefanie Voegele for a spot in the semifinals Friday night.
Venus Williams seemed to have her match under control, ahead 6-2 and 3-0 in the second set. Lepchenko rallied to win seven of the next eight games while a chilly drizzle fell in the middle of the second set and took a 1-0 lead in the decisive set. That's when Williams again found her game and pulled away by winning six of the final seven games.
Burdette, who won two NCAA doubles titles at Stanford, held her own against the world's top player and was tied at 4-all in the opening set. Burdette had a chance to get to 5-all a few moments later, but Williams won the next three points to close out the set.
Williams screamed loudly and pumped her fist after taking the set.
Williams broke out again when the second set was tied at 2-all, winning the final four games.
Burdette was proud of her effort against Serena Williams.
"I don't think you ever walk out on the court and say I'm going to beat Serena today," she said. "You just go out there and do your best."