Dinara Safina hasn't competed since withdrawing from the fourth round of the Australian Open in January and resumed training only on April 3. The Russian former world No.1 entered the Porsche Tennis Grand Prix in Stuttgart this week, the tournament at which she was runner-up last year, but will have to watch the state of her back closely in order for the potentially career-threatening injury not to reappear.

"Everybody, including my brother Marat (Safin), told me to take my time but it was really difficult because I wanted to come back on court so badly," said the 24-year-old Safina, seeded second at Stuttgart. "Right now I feel safe and comfortable, but I need to watch closely that it stays that way."

Safina is worried that the injury, which started bothering her in late 2009, could have a serious impact on her future: "My back injury is the worst you can get, because if things go wrong again, that might be it for my professional career altogether." (source: Yahoo, photo: Upali Wickramasinghe)

Rumors from this month's Family Circle Cup when Liezel Huber played with Nadia Petrova turned out to be true - Cara Black and Liezel Huber have split up, which ends one of the most legendary doubles teams of the era.

"On a personal note, my regular doubles partner, Cara Black and I are taking a mutual break from being exclusive doubles partners," Huber wrote.

"Both Cara and I are entered in Stuttgart with different partners but we continue to strive to do what we love most and that is to compete on the tennis court. I just wanted to thank everybody for their support. It was not any easy decision but we announced it today. We both want to be better players and right now it is best for us to just take a little break. We might get back together and we might not."

"Do not be surprised to see us playing with each other or with someone else in the next couple of months," Huber said. "It was not an easy decision. We have had a great partnership and we are appreciative of all the fan support."

Black and Huber shared the No.1 doubles ranking for over two years and won 29 titles together, including four Grand Slams and two Sony Ericsson Championships titles.

Black has spent the second most weeks in Tour history as the world's No.1 doubles player, trailing only Martina Navratilova. Huber has spent the third most weeks at No.1.

Cara Black entered the Porsche Tennis Grand Prix with Shahar Peer, while Liezel Huber's partner at the tournament is Jelena Jankovic. (source: On the Baseline, photo via Sony Ericsson WTA Tour)

Svetlana Kuznetsova, who had lost her last six finals, defeated world No.1 Dinara Safina 6-4 6-3 at the Porsche Tennis Grand Prix to win her first title since August 2007.

Kuznetsova was in command in the all-Russian final and sent Safina to a third final defeat of the season, after Sydney and Australian Open. Safina had five break points, but converted none of them, while Kuznetsova the 2004 US Open champion now ranked No. 9, converted two out of four.

Safina was playing her first tournament since becoming No.1. Kuznetsova will definitely remember this victory, it’s her first title in a long time, plus, she won the white Porsche. (photo via Yahoo)

World No.1 and top seed Dinara Safina once again used her impressive comeback skills to defeat Flavia Pennetta 3-6 7-5 6-0 and reach the Stuttgart final where she will face fellow Russian Svetlana Kuznetsova.

The world No.14 Pennetta seemed to be on a good way to victory as she won the first set and was close to winning the second, too. However, when Safina leveled at 5-5 in the second set, she never looked back and won the next eight games. Pennetta showed powerful groundstrokes, but as she lost her chances she became burnt out and Safina started dominating.

Safina now has a 6-0 head-to-head record against Pennetta.

Earlier, fifth seed Svetlana Kuznetsova crushed compatriot and second seed Elena Dementieva 6-4 6-2 with surprising ease in just 67 minutes to book her place in the Porsche Tennis Grand Prix final.

In Sunday’s final Kuznetsova will be trying to win her first tournament since New Haven in 2007. Safina will be going for her first title of the season, after losing in two finals in 2009, in Sydney and at the Australian Open. (photos via Sony Ericsson WTA Tour)

Defending champion Jelena Jankovic will not add the white Porsche to her car collection, as she was beaten in the quarterfinals of the Porsche Tennis Grand Prix by Flavia Pennetta.

I have to say it’s a pity we won’t see Jelena’s proud photos next to this luxurious car. Remember those with the red Porsche she won last year in Stuttgart?

The world No.14 Pennetta won the quarterfinal 2-6 6-4 6-4. Jankovic managed to come back from 2-0 down in the third set, and had her chance to end it as a victor, but dropped her serve in the seventh game once again. Pennetta then kept the lead and entered the semifinals on the first match point.

Pennetta will next face the winner of the match between world No.1 Dinara Safina and Agnieszka Radwanska. Second seed Elena Dementieva and fifth seed Svetlana Kuznetsova are the other semifinal pair. (photo: Ralf Reinecke)

Second seed Elena Dementieva and third seed Jelena Jankovic advanced to the quarterfinals of the Porsche Tennis Grand Prix in Stuttgart.

Dementieva played Agnes Szavay in the second round and despite being 4-1 behind in the first set, the Russian battled back to win the set in the tiebreak. Dementieva then cruised through the second set, but needed five match points to seal victory.

"I am still finding my feet on clay court. It is my first tournament of the year (on clay) and my footwork needs to improve," said Dementieva, who will next face Marion Bartoli, the winner over Caroline Wozniacki in the second round.

Defending champion Jelena Jankovic overcame Germany’s promising player Sabine Lisicki, who won Family Circle Cup this month, and beat 20th-ranked Patty Schnyder in the previous round in Stuttgart. The world No.42 Lisicki took Jankovic to three sets, but the Serb won 7-5 5-7 6-3 after two hours and 13 minutes of play.

Jankovic will encounter Flavia Pennetta or sixth seed Nadia Petrova in the quarterfinals. (photo: Ralf Reinecke)

Fourth seed Victoria Azarenka was upset 6-4 6-3 in the second round of the Porsche Tennis Grand Prix by claycourt specialist Gisela Dulko.

The world number eight Azarenka came into the Stuttgart event off the back of three tournament wins this season: Brisbane, Memphis and Miami.

Defending champion Jelena Jankovic lost just two games to Slovakian Dominika Cibulkova to reach the second round. She will next face Sabine Lisicki following her 6-4 6-3 win over Patty Schnyder.

In other first-round matches fifth seed Svetlana Kuznetsova had a hard task against German qualifier Andrea Petkovic, winning 6-4 5-7 6-1. Nadia Petrova also needed three sets to beat Zheng Jie 6-4 5-7 6-4, while Daniela Hantuchova defeated Alize Cornet 6-3 6-1. Also, Flavia Pennetta advanced with a 6-2 6-0 victory over Anna Chakvetadze. (photo: Ralf Reinecke)

Dinara Safina won her first match as world number one by defeating Sara Errani 6-0 6-1 to reach the second round of the Porsche Tennis Grand Prix.

Safina, who celebrated her 23rd birthday in Stuttgart on Monday, defeated the 37th ranked Errani in just 51 minutes.

Meanwhile, Jelena Jankovic, whose experiments with fitness regime ruined her game, decided to keep her expectations low: "I won't be thinking about defending the title here, it's more important for me to just get back to playing good tennis."

It’s bizarre and still painful that in Jankovic’s case it would’ve been better if she hadn’t worked at all, than those overly difficult trainings in the wrong direction. However, JJ learned her lesson: "You listen to your team and you think it will bring results. But my body just did not accept it [...] I am not doing any more experiments."

Great news is that the fourth-ranked Serb feels that her game is recovering: "I feel I am coming back into form."

World No.17 Dominika Cibulkova is awaiting Jelena Jankovic in the first round of the Porsche Tennis Grand Prix. (sources: BBC, Reuters; photo: safina-dinara.com)

Second seed Jelena Jankovic defeated Russia’s Nadia Petrova 6-4 6-3 in the Porsche Tennis Grand Prix final to win her second title in two weeks. The victory earned the world No.2 her eighth career title and a shiny red Porsche Carrera 911.

The 23-year-old Serb, who will on Monday return to No.1 in the rankings, also won the China Open last week and now has three titles this season.

Jankovic broke Petrova’s serve in the opening game to take the first set. In the second she led 3-1 with three break points for 4-1, but the 2006 Stuttgart champion Petrova tied at 3-3. Afterward, however, Jankovic regrouped and took the next three games for the title.

Jankovic improved her career record against the world No.18 Petrova to 6-2, with now three of those victories coming at the Porsche Tennis Grand Prix.

Before beating Nadia Petrova, Jankovic had defeated Alona Bondarenko, seed No.7 Vera Zvonareva, and sixth-seeded Venus Williams at the Porsche Tennis Grand Prix. (photo via Yahoo)

Second seed Jelena Jankovic edged sixth-seeded Venus Williams 6-7(8) 7-5 6-2, improved to 5-3 lifetime against the American, and set up a Porsche Tennis Grand Prix final against Nadia Petrova.

Russia’s Petrova advanced to the final in Stuttgart with a 6-4 6-4 win over Belarusian Victoria Azarenka, the 19-year-old player who upset fourth seed Elena Dementieva in the quarterfinals.

Jankovic, who was already assured of becoming the new women's world No.1 when the rankings are released on Monday, reached her first final at the Porsche Tennis Grand Prix  (last year she was beaten in the semis by Justine Henin) and will face the 2006 Stuttgart champion Nadia Petrova.

Jankovic and Petrova meet for the eighth time in their careers and the Serb leads their series 5-2. Interestingly, two of Jankovic’s victories over Petrova came at the Porsche Tennis Grand Prix, in 2004 (first round) and 2007 (quarterfinals). (photos: Getty Images)