Williams sisters to renew rivalry

Venus has been impressive in Charleston, but will get her biggest test from her sister in the semifinals. (Mic Smith/AP) CHARLESTON, S.C. -- After a historic

Venus has been impressive in Charleston, but will get her biggest test from her sister in the semifinals. (Mic Smith/AP)

CHARLESTON, S.C. -- After a historic day that saw both Serena and Venus Williams do double-duty to play and win two matches -- rain delayed their third-round matches on Thursday -- the two will face off for the 24th time in their careers in the semifinals of the Family Circle Cup. Venus opened play with a 6-2, 4-6, 6-2 win over Varvara Lepchenko and came back again to defeat 18-year-old Madison Keys 6-4, 6-4 to advance to her second semifinal of the year. Serena followed her lead, striking 34 winners on her way to beating Mallory Burdette 6-4, 6-2, and then defeated 6th seed Lucie Safarova 6-4, 6-1 in a rematch of last year's final.

It's been almost four years since Venus and Serena last faced off in the final of the WTA Championships in 2009, where Serena won 6-2, 7-6 to extend her slight lead in their head-to-head to 13-10. Due to their sisterly bond and familiarity, their matches have historically been tense, awkward affairs with each struggling to bring their best.

"I don't love playing her," Serena said. "If I win, I'm not super excited, and if I lose I'm really not excited."

Video highlights from their last match in Doha in 2009:

http://www.youtube.com/watch?v=g5ssKxb4b_Q

Serena may not be excited but the tennis-watching public has always tuned in for the sisterly duel. When Venus and Serena met in a Slam final for the first time in their careers at the 2001 U.S. Open final, the tournament shifted its schedule to accomodate CBS's request for the match to take place in primetime. That marked the first time the final of a Slam had ever been aired in primetime. Venus won that final 6-4, 6-2, but Serena would win their next five Slam final meetings. Their matches have rarely been blowouts, with 17 of their 23 matches going to either a tiebreak or a full three sets.

"I think we just both want to win," Venus explained, chalking up the tense nature of their matches as one borne from mutual respect. "I think we just both have so much respect for each other's game that makes it probably a little tougher because you know you're not going to get an easy win. You know you have to really just be on your game and play well every single time. So I think that's probably the toughest part."

For Serena, it's simply an issue of familiarity. "It's difficult because we know each other," she said. "I know where she's going to serve. She knows where I'm going to serve. And I know her patterns and she knows mine. She probably knows mine better than I do."

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It's hard to ignore the fact that the two, separated by just 14 months in age, are in different places in their careers these days. Serena is obviously in the midst of a late career resurgence, having taken over the No. 1 ranking from Victoria Azarenka in February and winning last week's Sony Open in Miami. The defending champion here, she has yet to drop a set heading into the semifinal. Venus on the other hand admits that she's still struggling with some inflammation in her back that forced her to withdraw from Miami last week and hasn't allowed her to serve at 100 percent this week. Without the ability to serve at her best, Venus will have a tough time defending her serve against her kid sister's aggressive returning.

Asked if she tried to keep her injury problems a secret from Serena after she saw the draw, Venus shook her head and laughed. "I think everybody knows about that." Nevertheless, Serena says she'll have to play her best.

"She's [the] toughest opponent I've ever played, and I think she's beaten me the most of any player, I think. We'll see how it goes."