At the ASB Classic in Auckland, world No.34 Zheng Jie won her first title since 2006, but the final match was an unfinished battle, as her opponent Flavia Pennetta retired at 2-6 6-3 2-0 with a low back injury. We're only a week into the tennis season, and the number of WTA players injured or ill is close to ten.

In the first round Zheng defeated Ayumi Morita, in the second eighth seeded Monica Niculescu, in the quarterfinals Lucie Hradecka, then third seed Svetlana Kuznetsova for the first time in their seven meetings, and finally Pennetta.

Zheng's first title came in Hobart in 2005, and since winning Estoril and Stockholm in 2006 she hasn't clinched any titles, even though she played two Grand Slam semifinals – at Wimbledon 2008 and Australian Open 2010.

Regarding Pennetta's injury, she started feeling it at 4-2 in the first set and an MRI scan will reveal how serious it is. (photo via ASB Classic)

A big tennis exhibition featuring six WTA stars (including two Top 10 members) took place on December 16-18 in Singapore and Italian Flavia Pennetta walked away with a victory bowl, defeating Poland's Agnieszka Radwanska in the final 6-4 7-5. Pennetta ended the tournament with a 3-0 win-loss record and besides the older Polish sister she defeated Daniela Hantuchova and 2011 US Open winner Samantha Stosur.

Samantha Stosur, the field's only Grand Slam singles champion, battled out for the third place and defeated Peng Shuai 2-6 6-4 6-4.

Thank you, On Court Advantage, for supplying us with all the information and photos!

Additional info: Talking about the 29-year-old Pennetta, today on Tennis.com I came across more of her revelations about the cheating of her ex-boyfriend, Carlos Moya, and how it affected her. The following excerpt is from her autobiography Dritto al Cuore (Straight to the Heart):

I put everything aside to support him. If you count the times I did it, probably the number is in itself ridiculous. My passion was him, I gave myself completely, and I lost my balance… People felt sorry for me and I could not even defend myself. It was as if I had lost my taste for things. I was trying to be numb towards life, not to feel pain. I did not even feel physical [pain]. A silly example: even when I was waxing, I did not even feel anything.

(photo credit: Sebastien Serandrei)

Never in their eight previous matches in the period of eight years, from 2002 to 2010, had Francesca Schiavone beaten Venus Williams, and at the December 3rd exhibition event in Milan, the Italian managed to beat both the Williams sisters, on top of showing her dancing skills by entertaining the 11,000 crowd to Michael Jackson's "Beat It" with Flavia Pennetta.

Schiavone defeated Venus 7-5 7-3, and then Serena 7-3 8-10 8-6. Pennetta also beat Venus, 7-6 7-2, but lost to Serena 6-8 7-3 7-3. The Williams sisters won the doubles 3-7 8-6 8-6.

Neither of the Williams sisters played competitive tennis since the US Open, however they did play another exhibition match recently, last month in Columbia, and Venus defeated Serena 6-4 7-6(5). (source: ESPN)

Thanks to Linda, who scanned childhood photos from Flavia Pennetta's autobiography "Dritto al cuore" (Straight to the Heart), and Women's Tennis Blog reader Tony, who retweeted me the pictures, you get to see the tennis star when she started out.

I love the romantic look that our Italian stars used to nurture when they were kids. Remember Sara Errani? Flavia looks beautiful in the long light dress, gazing at her racquet.

In the second photo you can see Flavia with her parents and elder sister Giorgia. They all play recreational tennis.

The little Flavia, who was introduced to tennis by her father at the age of five, grew up to be a successful tennis player in both singles and doubles, having achieved the ranking of No.10 in singles (the first Italian to crack Top 10) and No.1 in doubles.The 29-year-old has won nine singles titles and 14 doubles titles, including two Grand Slams.

In addition, Flavia is not afraid to speak out, which she recently reminded us of while talking about her relationship status.

Here's another photo that Linda showed me. Flavia was 15 years old here. I love the classy vintage look.

Tony and Linda, thank you for contributing to my series of childhood photos of WTA players, featuring Petra Kvitova, Sam Stosur, Li Na, Victoria Azarenka, and many others.

You have to love Flavia Pennetta. In an interview with Diva e donna the Italian admitted how former boyfriend and former tennis world No.1 Carlos Moya hurt her, because she believed they would be together for the rest of their lives, and how she can now hardly give her whole heart to a man, but the hilarious Flavia assured us that she's not missing out on the physical pleasures despite her single status.

The end of my relationship with Moya hurt me more than any injury. I put him before myself and you shouldn't do that for a man. Now I'm single, officially, but it wasn't so long ago that I last made love.

Pennetta and fellow tennis player Moya broke up in 2007, due to his cheating. Moya has since been with Spanish actress Carolina Cerezuela with whom he has a daughter now. (source: Gazzetta, photo: Ralf Reinecke)

Doubles team of Gisela Dulko and Flavia Pennetta will have a chance to defend their WTA Championships title from Doha by becoming the third doubles partnership to qualify for the year-end event, which will take place in Istanbul this year.

Dulko and Pennetta won their first Grand Slam title this year at the Australian Open and recently they played two Premier finals: Tokyo and Beijing. Also, they held the No.1 doubles ranking between them for eight months.

One more team can qualify in doubles, Victoria Azarenka and Maria Kirilenko or Vania King and Yaroslava Shvedova. Kveta Peschke and Katarina Srebotnik and Liezel Huber and Lisa Raymond are already in.

In singles there is also one spot left, which will be taken by either Agnieszka Radwanska or Marion Bartoli. Already qualified are: Caroline Wozniacki, Maria Sharapova, Petra Kvitova, Victoria Azarenka, Li Na, Vera Zvonareva and Samantha Stosur.

Additional info: Pennetta recently at the China Open became only the second woman in history who defeated No.1 players in both singles and doubles on the same day. (photos: Ralf Reinecke)

Last week at the China Open Flavia Pennetta defeated singles and doubles No.1s on the same day – Caroline Wozniacki and Liezel Huber – thus joining the legendary Steffi Graf as the only other player in history to achieve the feat.

In the Friday's Beijing singles quarterfinals, Pennetta upset top-ranked Wozniacki, and then, together with Gisela Dulko, beat the doubles team of Liezel Huber and Lisa Raymond in the semifinals.

Graf defeated the No.1-ranked player in singles and doubles by winning over Martina Navratilova in Berlin, in 1986, when Navratilova was on top of both the singles and doubles rankings.

Moreover, only five players in history managed to beat both the No.1s at the same tournament: Steffi Graf in 1986, Jana Novotna in 1996, Lindsay Davenport in 2008, Venus Williams in 2009, and now Flavia Pennetta. (source: WTA Tour, photo: sr_cranks)

Pennetta had lost all five of their previous encounters.

The 3-6 6-0 7-6(2) win over the world No.1, who’s occupied the position for a year now, booked Pennetta a clash with No.11 seed Agnieszka Radwanska, whose opponent, Ana Ivanovic, retired.

Ana Ivanovic recorded three solid victories en route to the China Open quarterfinals, against Kimiko Date-Krumm, Svetlana Kuznetsova, and Vera Zvonareva, having lost just ten games to reach the final eight, but a left low back injury sustained in Tokyo last week forced her to retire in the second set against Radwanska and the Pole is through to the semis.

"I have been doing lots of treatments on it, but it hasn't been really getting much better," said Ivanovic about the injury due to which she left the tournament while trailing 6-3 3-2.

Radwanska had a milestone victory last week at the Toray Pan Pacific Open. (photos: sr_cranks)

US Open quarterfinals preview: Serena still the tournament favorite

We are now at the quarterfinals stage of the tournament and Serena looks almost unbeatable to me at this point (join our poll to vote who has the best chance of shaking Serena's dominance this US Open). Let’s have a closer look at the upcoming quarterfinal match-ups.

CAROLINE WOZNIACKI versus ANDREA PETKOVIC

Wozniacki has had a really good draw so far in this tournament and to me she was not all that convincing in her victory against Svetlana Kuznetsova. I am not sure how strong her form actually is. She was down 4-1 in the second set against Kuznetsova who is also not in her best form at the moment.

Andrea Petkovic looked convincing in her last two matches but she has not faced any really strong players so far in this tournament. Petkovic is also playing with an injured knee but it seems to be holding up fine so far in the tournament. Wozniacki and Petkovic are 1-1 in their career matches. Petkovic won this year on a hard court in Miami and Wozniacki won on an indoor clay court in Stuttgart.
In order to beat Wozniacki you have to be able to get by her with some firepower and be patient enough to work the point a few times. I believe Petkovic has these capabilities. Andrea is fired up like I have never seen her before and I think she is also mentally ready to beat someone like Wozniacki in a Grand Slam quarterfinal.

Assuming that Petkovic’s knee holds up, I pick her as my favorite in a very close match.

SERENA WILLIAMS versus ANASTASIA PAVLYUCHEKOVA

Pavlyuchenkova is a former junior world number 1 and she is getting better and better recently. Her game can be dangerous and she beat two strong players, Jelena Jankovic and Francesca Schiavone, in the last two rounds.

Serena has only been tested for one set in this tournament, which was against Victoria Azarenka. Other than that she has been cruising and to me she looks almost unbeatable at this point. It seems like she is in that kind of form where she always has another gear ready if she needs it.

I believe Serena is too strong and will win this match and most likely go on to win the tournament.

ANGELIQUE KERBER versus FLAVIA PENNETTA

Pennetta was not very successful in the US Open series but seems to be getting better and better in this tournament. She beat Maria Sharapova in a tough three setter and in the last round she had a straight sets win over 13th seed Shaui Peng.

Angelique Kerber from Germany is a surprise quarterfinalist. She will play her first Grand Slam quarterfinal match against Pennetta and before the tournament she was ranked number 92 in the world. Kerber is a lefty that hits a pretty flat ball from the baseline, well-suited to the US Open court surface.

Kerber is certainly in good form and dangerous on this court surface. Nevertheless, I think Pennetta will be too strong in this Grand Slam quarterfinal match.

SAMANTHA STOSUR versus VERA ZVONAREVA

Stosur leads the head-to-head in this match-up by 7-2. I think she has had great success against Zvonareva by hitting balls with a lot of spin that bounce high and get outside of Zvonareva’s comfort zone. Zvonareva prefers to play a flatter game where the balls are fast and relatively low.

One thing to keep in mind is that Zvonareva showed some impressive form in her straight sets win over Sabine Lisicki in the last round and Stosur has had two tough three setters in the previous two rounds. Also the ball does not bounce very high at the US Open, which is the main reason I think Zvonareva plays so well at this tournament.

This is another really close match but I pick Vera Zvonareva to win this one with good chances to go on the finals afterwards.

So much for my quarterfinal picks. Hopefully we get to see some great matches and let me know what you guys think in the comments section.

Florian Meier is a professional tennis instructor from Germany. He specializes in improving players through the use of Tennis Video Instruction. He wants to reach tennis players from all over the world with his website Online Tennis Instruction. (photos: © Neal Trousdale)

It's over

The Russian said she hadn’t felt comfortable with most of her game and she lost a three-setter the first time this year (she had a 12-0 record in 2011 when the deciding set had to be played). After being down 3-0 and 4-1 in the final set, Sharapova managed to get the score to 4-all, 15-30 on Pennetta’s serve. Then the downward spiral started for the Russian and the 26th-seeded Pennetta won all the remaining seven points to earn one of the biggest victories of her career in two and a half hours.

Of course, the 2006 US Open champion Sharapova didn’t accept the defeat lightly:

It's disappointing to lose in New York. Losing isn't fun for anyone because we work to win. We don't work to try to lose. So when we're faced with a position where we can win and we didn't in the end, it's tough.

(photo: sr_cranks)