Serena Williams' awe-inspiring comeback has suffered a shocking setback – the champion's 12-match winning streak has been cut short by a retirement! It might be Serena's tactical decision to prevent her from exhaustion or injuries ahead of the US Open, but it still is disappointing that her string of victories is ending in such a way. Serena retired with a right toe injury prior to her second-round match against Samantha Stosur at the Western & Southern Open.

After almost a year away with injuries and illness, Serena returned like a storm, winning Stanford and Toronto and following it up with a victory against Lucie Gradecka in the first round of Cincinnati this week.

Update: Here's Serena's press conference following the withdrawal.

(photo courtesy of FIJI Water)

Caroline Wozniacki’s form ahead of the US Open is becoming worrying – the Dane suffered her second straight loss in an opening match and not even the presence of her rumored boyfriend Rory McIlroy did her good today against Christina McHale, an American ranked 75 placed below her.

In the second round of the Western & Southern Open, McHale broke Wozniacki’s poor serve five times during the two-set encounter which finished 6-4 7-5. Last week at Toronto Wozniacki lost her opening match against Roberta Vinci with the same score.

The world No.1 has lost only 12 matches this season, but early exists have piled up recently, including her retirement against Sofia Arvidsson in the second round of Bastad last month. (photo: © Neal Trousdale)

In the beginning it seemed Serena Williams would cruise to a quick victory over world No.49 Lucie Hradecka in the first round of the Western & Southern Open in Cincinnati, as the American stormed through the first set with a 89% of first serve points won.

However, at 5-1 down in the second set, the Czech fired back and frustrated Serena when she leveled at 5-5 by breaking the American's serve twice. The tiebreak was played, but Hradecka had an unglamorous finish when she lost the tiebreak 7-5 with a double fault.

Both players hit 31 winners, but Hradecka committed more unforced errors. Final score: 6-3 7-6(5).

Serena's rankings improved on Monday from No.80 to No.31 following her triumph at the Rogers Cup. Together with her Stanford title, Serena is now on a 12-match winning streak. (photo: © Neal Trousdale)

Earlier this year world No.1 Caroline Wozniacki was headlining the "Adidas is all in" campaign alongside stars from the worlds of fashion, sport and music such as: Leo Messi, Katy Perry and David Beckham.

The second phase of the campaign has been launched recently, celebrating inspirational women who constantly dare to push boundaries to reach their goals. Besides athletes, it features DJs and musicians such as Katy Perry and DJ Baby G. Check out the above ad, it's super cool! Read more »

The US Open is approaching and it's time for reviewing what tennis stars will be wearing at the final Grand Slam of the season. The most famous brands, Adidas and Nike, are always the first to grab attention, so let's see what they have prepared for their biggest names.

Ana Ivanovic has been sporting a beautiful blue Adidas Fall Adizero Dress and at the US Open the 23-year-old Serb will wear the same dress, only in pink, or as they officially call it, in "sharp red". The dress has an open back and a delicate design on torso.

Serena Williams will finally give credit to her Nike clothes at a major and her two recent victories at Premier-level events will insure she pays back to all the time Nike made an outfit for her even though she didn't play a tournament.

Serena has two dresses for the 2011 US Open. During the day she will wear Autumn Smash Hard Court Dress in red, and for night matches she is expected to wear the blue version.

Maria Sharapova is also equipped for both day and night. The 2006 US Open champion has a Maria Ace Day Dress in gray and light purple with fluorescent red linings. Sharapova's night dress is not the same as the day one just with a darker color scheme, the style is compatible but different. Read more »

Nothing can be said except absolute respect for Serena Williams who won her second straight Premier-level title with a convincing 6-4 6-2 victory over Samantha Stosur in the final of the Rogers Cup in Toronto. Serena doesn’t need months to get back in shape and warm up for big matches – after almost a year away from the courts Williams returned in style winning two of four tournaments she entered.

In the Rogers Cup final against tenth-seeded Stosur, Williams kept her serve throughout, faced just one break opportunity, won 89% of points on her first serve, and finished the match in style, firing four aces in the last game.

Ahead of the US Open, Serena is still cautious of calling herself a favorite: "I went through a lot of things physically, mentally and emotionally, and going through so much so I am just taking it one day at a time and kind of like one match at a time."

The unseeded Williams, whose rankings dropped because of her long time away from the Tour, crushed Alona Bondarenko 6-0 6-3 in the first round, and then Julia Goerges, Zheng Jie, Lucie Safarova, Victoria Azarenka and finally Samantha Stosur. The victory saw Williams propel from No.80 to No.31 in the rankings. Before her injury layoff Williams was ranked No.1. (via Reuters, photos via WTA Tour)

Serena Williams extended her winning streak to ten matches by defeating Victoria Azarenka 6-3 6-3 in the semifinals of the Rogers Cup. In her second straight final Williams will face Samantha Stosur.

The fourth-seeded Azarenka reached the semifinals having lost just six games, but Williams is in her Grand Slam-winning form ahead of the US Open. The American won eight of the last 11 points in the first set and 16 of the last 19 points in the second.

Samantha Stosur fell out of the Top 10 on Monday but with a 6-2 5-7 6-2 victory over Agnieszka Radwanska in the semifinals of the Rogers Cup the Australian will regain the spot. Radwanska was on a nine-match winning streak, having won Carlsbad, and at the Rogers Cup she hadn't dropped a set all week.

Williams and Stosur have played each other five times so far, and Williams leads their head-to-head record 3-2. (photos: © Neal Trousdale)

Serena Williams' comeback is ever more impressive. Every day the American is reminding us of how unprecedented tennis player she is, and even though she looked tired in her last match, a win is a win, and she is now only two matches away from winning her second straight title in only her fourth tournament since a year-long layoff which included a persistent foot injury and a serious problem with a blood clot in her lungs. Williams reached the semifinals of the Premier-level Rogers Cup by overcoming also unseeded Lucie Safarova 4-6 6-3 6-2. Victoria Azarenka will be Williams' next opponent. In the quarterfinals Azarenka ended the run of 135th-ranked qualifier Galina Voskoboeva, who eliminated Marion Bartoli, Flavia Pennetta and Maria Sharapova from the tournament.

The other semifinal will feature Samantha Stosur and Agnieszka Radwanska. Stosur took out Roberta Vinci, who scored major upset early in the tournament by beating world No.1 Caroline Wozniacki and later she defeated Ana Ivanovic. Radwanska reached the final four with a 6-4 6-3 victory over Andrea Petkovic. (photo courtesy of FIJI Water)

The Grand Slam-like field at the Rogers Cup is rapidly losing its biggest stars. Six major champions were in action on Thursday and only one survived – the mighty Serena Williams. The American returned only recently to competitive action and has already clinched a Premier-level title (Stanford) and is steadily making her way through the Toronto event.

Ana Ivanovic (Roland Garros 2008 winner), Li Na (Roland Garros 2011 winner), Petra Kvitova (Wimbledon 2011 winner), Francesca Schiavone (Roland Garros 2010 winner) and Maria Sharapova (three-time Grand Slam champion) all lost in straight sets in the third round of the Rogers Cup.

After defeating Alona Bondarenko 6-0 6-3 in the first round and Julia Goerges 6-1 7-6(7) in the second, Williams overcame Zheng Jie in an entertaining third round match for a 4-6 6-3 6-3 victory. The world No.82 Zheng, who is trying to improve her lost ranking, was two points from a 4-2 lead in the third set when Williams did her signature thing – brought her best game when it mattered the most.

Williams' opponent in the quarterfinals will be Lucie Safarova, who defeated eighth seed Francesca Schiavone 6-3 6-3 in the third round. Other quarterfinal pairs: Roberta Vinci vs. Samantha Stosur, Agnieszka Radwanska vs. Andrea Petkovic and Galina Voskoboeva vs. Victoria Azarenka. (photo courtesy of FIJI Water)

World No.135 Galina Voskoboeva of Kazakhstan had to qualify for the main draw of the Rogers Cup and the extra matches she played are not preventing her from scoring one great victory after the other: in the first round she upset ninth seed Marion Bartoli, afterwards Flavia Pennetta, and her latest success story is a well-deserved victory over fifth seed Maria Sharapova in the third round.

In the first set Voskoboeva faced no break points and she simply built on the quickly-established 4-2 lead to take the first set 6-3. The second set was more closely contested, with both players having ups and downs, earned and lost opportunities, but Voskoboeva didn't let the opportunity slip away and won the second set 7-5.

Voskoboeva's opponent in the quarterfinals will be fourth seed Victoria Azarenka, who defeated qualifier Maria Jose Martinez Sanchez 6-1 6-2.

In her first tournament since winning Wimbledon, Petra Kvitova was stunned by Andrea Petkovic decisively, 6-1 6-2. Li Na is also out – she fell to Samantha Stosur 6-2 6-4 in the third round. Roberta Vinci, who upset world No.1 Caroline Wozniacki in the previous round, has progressed to the quarterfinals with a 7-6(3) 6-2 win over Ana Ivanovic.

A bad day for Grand Slam champions at Rogers Cup, so far this Thursday four were in action and four lost: Ivanovic, Li, Kvitova and Sharapova. (photo: © Neal Trousdale)