Second seed Serena Williams beat one of the hottest players lately – seed No.10 Flavia Pennetta – 6-4 6-3 and reached the semifinals of the US Open where her opponent will be wildcard Kim Clijsters, the sensation of the tournament.

The defending champion Williams is 7-1 lifetime against Clijsters, and 7-0 on hardcourts, but the mother of little Jada is far from the "elephant" she used to feel like when she picked up a racquet for the first time after giving birth (Clijsters’ quote: "I felt like an elephant sometimes, just trying to move. Even two steps was terrible.")

Williams has only the greatest things to say about her next opponent:

I've seen how she has been moving. It seems like she's even faster than she was before. I was thinking maybe I should have a baby and then I'll come back faster. I have nothing but good feelings for Kim. She's such a good-hearted person. She takes tennis seriously, but life even more seriously. That's the type of person I am, too.

Despite so many victories of the 11-time Grand Slam champion Williams over Clijsters, the two are expected to provide a blockbuster semifinal. After all, Williams won the US Open in 1999, 2002 and 2008, and Clijsters won it in 2005. (photo via Sony Ericsson WTA Tour)

I have already shared it on Women's Tennis Blog that Dinara Safina will remain No.1 in the WTA rankings whichever course of events at the US Open, but Safina’s top ranking will be short lived if Serena Williams reaches the US Open finals.

If the second-ranked Williams progresses all the way to the finals, she will take Safina’s place in the rankings just one week after the US Open, in the September 21 rankings.

Slamless Dinara Safina has been ranked No.1 since April 20, 2009, even though Serena Williams won three of the last four Grand Slams.

Will defending champion Serena Williams achieve the feat and hopefully end the tiring debate about the rankings?

Additional info: Safina was upset in the third round of the ongoing US Open, while Williams will play her quarterfinal match against Flavia Pennetta later today. (source: ESPN, photo by our reader Jacob)

Belgian Kim Clijsters may be playing her first Grand Slam since the 2007 Australian Open, but has quickly assured the world that she is the player to beat on the WTA Tour. Along with teenager Melanie Oudin, tennis mom Clijsters is marking the 2009 US Open, being unranked and playing only her third tournament after a two-year-long break.

After victories over seeds number 14 and 3, Marion Bartoli and Venus Williams respectively, Clijsters sent packing yet another seed, No.18 Li Na, and remarkably reached the semifinals of the Grand Slam she won in 2005. Clijsters beat Li 6-2 6-4 in 63 minutes.

Progressing to the final four, Clijsters has equaled Zheng Jie’s Wimbledon 2008 campaign – the best performance by a women's wildcard in a Grand Slam. In addition, the former world No.1 Clijsters is expected to leap back into the Top 50.

Clijsters' opponent in the semifinals will be holder Serena Williams or in-form Italian Flavia Pennetta. (photo: Stephane Martinache)

Melanie Oudin won’t have the pleasure of meeting yet another Russian at this US Open, as Caroline Wozniacki of Denmark will be her next opponent, who eliminated the last Russian in the draw, sixth seed Svetlana Kuznetsova.

Ninth seed Caroline Wozniacki reached her first Grand Slam quarterfinal by defeating Kuznetsova 2-6 7-6(5) 7-6(3). Wozniacki converted her third match point, having wasted one at 5-4 and one at 6-5 in the third set.

"I hit too many unforced errors and I couldn't control my emotions. And I wanted it so much, so it was pretty hard to control," world No.6 Kuznetsova said. "All credit to her. But you can't win against anybody with those errors. No chance."

The world No.8 Wozniacki was the highest-ranked player never to have been among the final eight at a Grand Slam. World No.18 Virginie Razzano is that player now. (source: Sony Ericsson WTA Tour, photo: Ralf Reinecke)

Maria Sharapova may be out of the US Open, but she’s always the champion of endorsement deals and fashion. Along with ATP player Rafael Nadal and other Nike superstars, Sharapova is modeling Nike’s AW77, adding her own personality and attitude to the Geoff Hollister's signature hoody.

The athletes were photographed in three cities over four months, by renowned photographer David Sims, styled/directed by Karl Templer.

Behind-the-scenes photos are available here.

UPDATE: There is this video of the photo shoot as well.

(source: Down the Line)

World No.70 Melanie Oudin can now be called the slayer of the Russians, as the 17-year-old American hope defeated Anastasia Pavlyuchenkova in the first round, fourth seed Elena Dementieva in the second, seed No.29 Maria Sharapova in the third, and now Nadia Petrova in the fourth.

Oudin won just one game in the opening set, but the second was quite a different story. When the 13th-seeded Petrova was serving for a 5-3 lead, Oudin broke back to level at 4-4, and step by step forced a tiebreak which she decisively won 7-2. Oudin then rolled through the deciding set, taking advantage of Petrova’s 22 unforced errors. Final score: 1-6 7-6(2) 6-3.

As the excitement of the past week didn’t catch up with determined Oudin, she’ll be playing her first Grand Slam quarterfinal. Oudin’s opponent in the final eight will be either yet another Russian, sixth seed Svetlana Kuznetsova, or ninth-seeded Caroline Wozniacki of Denmark.

In addition, Oudin’s ranking will rise to at least No.45 when the US Open is over. (photo via Life.com)

Former world No.1 Kim Clijsters of Belgium, playing her first major and only her third tournament since returning to the Tour after a two-year-long break, crossed a big obstacle in the form of American third seed Venus Williams to progress to the quarterfinals of the 2009 US Open.

It was a strange match. The 2005 US Open champion Clijsters was winning game by game to unexpectedly bagel Williams in the first set. Then, again unexpectedly, the 2000 and 2001 US Open champion Williams bageled Clijsters in the second set. Such course of events made the third set totally unpredictable. However, in that final set Clijsters made what to proved to be a decisive break in the third game of the set, and even though Williams had two break points to level at 5-5 Clijsters held her serve and won the set 6-4.

Therefore, the final score was 6-0 0-6 6-4.

Clijsters' opponent in the quarterfinals will be No.18 seed Li Na of China, whom she leads 3-1 in career meetings. (photo via Life.com)

Second seed Serena Williams lost just two games against seed No.22 Daniela Hantuchova to advance to the quarterfinals of the 2009 US Open.

The Slovakian world No.24 was a good competitor until 2-2 in the first set, but since then, before you knew it, the American defending US Open champion won the match by winning all the following games.

Nevertheless, Hantuchova has made her best US Open run since a quarterfinal finish as a teenager in 2002.

Serena's next opponent will be the winner of the Flavia Pennetta vs. Vera Zvonareva match. (photo via Sony Ericsson WTA Tour)

America’s third-highest ranked WTA player Melanie Oudin reached the fourth round of a second straight Grand Slam, pulling off a comeback victory over Maria Sharapova, while world No.1 Dinara Safina finally crashed out of the US Open, having survived two close encounters in the first two rounds.

The 17-year-old Oudin, ranked 70th in the world, beat No.29 seed Maria Sharapova 3-6 6-4 7-5. The Russian hit 63 errors, and less than half as much winners, 30.

Let me remind you that in the previous round Oudin ousted fourth seed Elena Dementieva.

In the first round against world No.167 Olivia Rogowska, the top-seeded Safina lost the first-set tiebreak and rallied from a 3-0 down in the deciding set to advance. Against world No.67 Kristina Barrois in the second round Safina also lost the first set tiebreak and was trailing 2-0 in the third set. Finally, Petra Kvitova, ranked No.72, conquered the shaky world No.1 in another nail-biter, even though Safina had held three match points. Final score: 6-4 2-6 7-6(5).

As everyone knows, Safina is yet to win a Grand Slam title, but will remain on top of the rankings regardless of who wins the US Open title. (photo via Sony Ericsson WTA Tour)

After her probably toughest loss, Ana Ivanovic has decided to forget about tennis for a week or two – before tournaments in Tokyo and Beijing – and then hopefully end the yucky season in a worthwhile manner.

The world No.11 Ivanovic revealed some of her inner issues in her latest diary entry:

It's no secret that this is the most difficult time of my career so far. Losing in the first round of the US Open hurt a great deal, I can tell you that.

I feel mentally exhausted. This season has been very difficult in terms of my health and form: even though I'm in great shape in terms of my stamina and speed, I've been picking up so many small injuries. Just when I felt like I was close to getting back into my rhythm, I would feel pain in a new place, and then I'd feel like I'm starting all over again.

It's obviously affected my confidence and I've overanalysed it too, and let if affect me far too much – not just the injuries, but my desire to get back to the top.

Additional info: Here’s how the famous tennis coach Nick Bollettieri would approach Ana's chronic problem: "If she came to me I would say tell me every single thing that's on your mind. Everything! Do you still like the game? Have you lost your confidence? Are you afraid? Did you have a bad relationship?" (photo: Ralf Reinecke)