Venus and Serena Williams say they've seen little of each other for the past week because of their busy schedules. That will change today, when they meet in the Sony Ericsson Open semifinals.

Serena Williams advanced to the semifinal of the Sony Ericsson Open on Wednesday, overcoming a dismal start to beat unseeded Li Na of China 4-6, 7-6 (1), 6-2. [Sina.com]

The 20th showdown between the sisters ensures a finalist from the family on Saturday. The Williamses have won eight of the past 11 Key Biscayne titles.

"I'm always going to be up for 'V,' because she's playing really well and always playing me super tough," top-ranked Serena said.

She advanced first on Wednesday, overcoming a dismal start to beat unseeded Li Na of China 4-6, 7-6 (1), 6-2. Five hours later she was joined by No. 5-seeded Venus, who beat No. 26 Iveta Benesova of the Czech Republic 6-1, 6-4.

The other semifinal will be between No. 8 Svetlana Kuznetsova and No. 11 Victoria Azarenka.

No. 3 Novak Djokovic became the first men's semifinalist by beating No. 10 Jo-Wilfried Tsonga 6-3, 6-4, ending a four-match losing streak to the Frenchman.

"I have to be very happy, because I have been struggling to find a way to win against him in the last four encounters," said Djokovic. "It was all so close, so I just knew that I needed to stick in and try to wait for my chances and be aggressive. Today I think I tried to be closer to the line, more in control, and just put the pressure on him. Overall, I'm really satisfied."

For a place in the final, 2007 champion Djokovic will meet either two other former winners, Roger Federer or Andy Roddick.

Venus leads her family rivalry 10-9. She has won the past two meetings and has a 2-1 advantage at Key Biscayne.

"Playing her, it's like I have to automatically be on a different level, because she's already playing on a different level," Serena said. "Her balls are harder and her serve is way bigger. And it's super fun to hit these serves that are like 120 mph. It's frustrating but at the same time fun."

Venus has three titles in the tournament, but the most recent came in 2001. Serena seeks her sixth Key Biscayne title, which would break the record she shares with Steffi Graf.

The bid nearly ended against Li, who raced to a 5-0 lead while Serena looked lethargic in the 80-degree (27-degree C) sunshine. Several times she declined to chase shots that seemed within reach.

"Wake up!" one spectator shouted.

"Maybe I was tired, but that's still not an excuse really," Serena said. "I definitely wasn't moving my feet at all. I just wasn't doing anything that made a lot of sense at all."

Midway through the first set, her father Richard Williams left his seat in the stands and positioned himself courtside near the baseline. He's the sisters' coach, and while he said little, he lifted Serena's spirits.

"I just felt like he was there really supporting, and I felt the support more when he was up close as opposed to in the stands," she said. "I just felt like I could take it up to another level."

She did, moving better and punctuating her shots with more emphatic grunts as the match slowly swung her way. There were no service breaks in the second set, but the unseeded Li failed to convert six break-point chances. The last came at 5-all, and Williams erased it with a service winner.

Li made things easy for Williams in the tiebreaker by committing six unforced errors. As the third set began to slip away from Li, she vented her frustration by slamming a ball against the backstop on the far end of the court.

"I gave her the tiebreak," Li said. "I couldn't focus in the final set. After she won the second set, I didn't think I had a chance."

Venus' victory was more straightforward, although she had a brief lapse in the second set when she fell behind 3-love. Smacking serves at up to 120 mph (195 kph), she hit eight aces and won 21 of 26 first-serve points.

Venus is 15-1 this year, while Serena is 20-2 and won her 10th Grand Slam title in January at the Australian Open. Venus has been the more consistent Williams in the past week, while Serena managed the curious feat of reaching the semifinals despite losing five consecutive games three times in her past two matches.

"I need to be more consistent in my play," she said. "I don't have to be out there going three sets. That's what I think it tells me more than anything."

She improved her record at Key Biscayne to 51-5, with one loss since 2001 - to her sister.

(Agencies via Shanghai Daily April 2, 2009)