The 2012 US Open semifinals feature three reigning Grand Slam champions (Victoria Azarenka, Maria Sharapova, Serena Williams), one reigning Grand Slam runner-up (Sara Errani), and all the three London Olympics medalists. What more can you ask for? Our contributor Omair is back in action, giving us his take on the upcoming semifinal match-ups. First up, Victoria Azarenka vs. Maria Sharapova.

For the second time this year, Azarenka and Sharapova will square off at a Grand Slam. In the Australian Open final in January, Azarenka demolished Sharapova 6-3 6-0. This time, Sharapova will try to reach her third major final of the year, while Azarenka will work for her second.

Azarenka leads the head-to-head against Sharapova by a slim margin of 5-4. They have already met three times this year, each time in the finals, with Azarenka coming out on top in two of the meetings. However, it was Sharapova who won their last encounter at Stuttgart.

Let's see their average stats for the matches played until the 2012 US Open quarterfinals.

The top-seeded Azarenka lost one set en route to the last four, while Sharapova survived three-setters in her last two matches. If you look at the stats, not much differentiates the two, but there will be a few key factors that both will need to work on. Read more »

In her first Grand Slam quarterfinal since Roland Garros 2008, Ana Ivanovic was unlucky to bump into Serena Williams and suffer the same fate as most Serena's recent opponents – a short stay on the court. Going up 3-0 in the first set against Ivanovic, Serena had won 23 straight games! The match finished in just 58 minutes and Serena won stunning 26 of 29 points on her first serve, while hitting 12 aces to Ivanovic's zero. Final score: 6-1 6-3.

Ivanovic has to find satisfaction in improving her game and reaching her first US Open quarterfinal, accepting the fact that Serena has been pretty much unbeatable lately. This summer she won Wimbledon and the Olympic gold in both singles and doubles, while at the US Open she's been a champion three times and has made at least the semifinals the last four times she played the tournament.

Serena's semifinal opponent will be Sara Errani, the first Italian US Open semifinalist in the Open Era, who will become No.1 in doubles after the tournament. To advance to the final four, Errani beat her best friend and regular doubles partner Roberta Vinci 6-2 6-4. The other semifinal will feature Victoria Azarenka and Maria Sharapova. (photo: Ralf Reinecke)

Rain stretched it over two days, it went to three sets and at 4-4 in the last set it was still unclear whether Maria Sharapova or Marion Bartoli would have the edge and advance to the US Open semifinals. The Russian then broke the persistent Bartoli and in the next game established herself as the winner, 3-6 6-3 6-4.

On Tuesday, Bartoli started the quarterfinal on fire, building a 4-0 lead, even though in the fourth game, leading 40-0 on Sharapova's serve, a bad line call prevented Bartoli from breaking Sharapova to love immediately and allowed the Russian to come back to 40-40. Eventually, the still erratic Sharapova gave the game away by double-faulting on Bartoli's fourth break point. Soon afterwards, the match was suspended due to rain and it turned out it would resume on Wednesday. Read more »

After winning the second set, Samantha Stosur raised our hopes that she could finally beat Victoria Azarenka for the first time in their seven meetings, and in the thrilling third set she recovered from 1-3 down to 4-4 and from a devastating 0-4 in the tiebreak to 5-5. But with a nice drop shot, world No.1 Azarenka earned her first match point and finished the job right away, 6-1 4-6 7-6(5).

After just nine minutes of play in the first quarterfinal of the 2012 US Open, top seed Azarenka raced to a 3-0 lead facing the defending champion, against whom she was victorious in straight sets in all their six previous meetings. The rain then started falling and play was suspended for one hour and 17 minutes, but when the match resumed Azarenka just continued where she started and eased through the first set 6-1. The seventh-seeded Stosur was determined to stop the unfavorable tradition and won her first set against Azarenka in 14 tries, when a crucial break in the seventh game of the second set earned her a confidence-boosting win over Azarenka, whose 2012 record on hard surfaces coming into the match was an astonishing 30-2, while at this US Open her scorelines leading up to the quarterfinals look like this: 6-0 6-1, 6-2 6-2, 6-0 6-1, 6-2 6-2. As described in the introduction, Azarenka had the edge in the third set and is now 7-0 career against Stosur.

Azarenka's semifinal opponent will be either Maria Sharapova or Marion Bartoli, whose quarterfinal is now suspended due to rain. (photo: © Neal Trousdale)

Eighteen Grand Slams after her last Grand Slam quarterfinal in 2008 when she went all the way to the title at Roland Garros, Ana Ivanovic is finally in another Grand Slam quarterfinal and actually her first ever at the US Open.

To advance to the last eight Ivanovic even produced one bagel against Tsvetana Pironkova, 6-0 6-4. Pironkova, the 2010 Wimbledon semifinalist, held serve just once in the match and Ivanovic converted all seven of her seven break points. Even though troubled by a neck injury, Pironkova made a fightback in the second set, including breaking Ivanovic when she was serving for the match, but the Serb broke back immediately to ensure progress.

Ivanovic's quarterfinal opponent is Serena Williams and Ivanovic's knees must be shaky. Why? Serena's US Open win-loss record is 62-9, her 2012 record is 50-4, she won her previous four matches with scores 6-1 6-1, 6-2 6-4, 6-4 6-0 and 6-0 6-0 in the fourth round against Andrea Hlavackova, while her career record against Ivanovic is 3-0 (all straight-set wins) and two of those victories came at the US Open. I had my hopes high for Ivanovic to finally come back to the quarterfinal stage of a Grand Slam, but this obstacle, I'm afraid, she'll not overcome.

Other quarterfinal pairs: Victoria Azarenka (1) vs. Samantha Stosur (7), Maria Sharapova (3) vs. Marion Bartoli (11) and Sara Errani (10) vs. the winner of the match between Roberta Vinci (20) and Agnieszka Radwanska (2).(photo: © Neal Trousdale)

The US Open run of Laura Robson may have ended at the hands of defending champion Samantha Stosur in the fourth round, but the 18-year-old Brit's success in New York was such a confidence booster that she can't wait to challenge "the top girls" at the upcoming tournaments, including the next year's Australian Open.

After taking out Kim Clijsters, three-time US Open champion and one of the best players ever, then Li Na, last year's French Open champion, Laura fell to Stosur 6-4 6-4, but only after saving eight match points! Not only was this a huge achievement for her, but also for her country, who hadn't had a WTA player in a Grand Slam round of 16 since 1998.

Despite the lifted confidence, Laura is yet to embrace her increased celebrity status. On the morning of her match with Stosur, in her hotel there was a camera crew waiting for her, and she herself got excited thinking that there was some famous person in the hotel!

Robson believes that Asian courts will suit her well and is now heading to Guangzhou, China, to be followed by Tokyo, Beijing and Osaka.

How much of Robson's success can be attributed to her new coach, the intense Zeljko Krajan, who joined Robson's team after his short recent cooperation with Jelena Jankovic and Dominika Cibulkova? According to Robson, a lot, especially his specific tactics. On the other hand, Krajan believes that Robson has limitless potential and one of his tasks is to open her eyes and show her how much she has.

At No.89, Robson is the youngest player in the Top 100, while after the US Open her ranking is expected to rise to about No.75. (photo: Moo's Tennis Blog)

For the second year in a row at the US Open, Ana Ivanovic defeated Sloane Stephens in the third round. The question now is, can the Serb overcome the obstacle of the Grand Slam fourth round that has troubled her since her 2008 French Open trophy?

Sixty-two spots higher in the WTA rankings than in their last year's US Open match, the 19-year-old Stephens, the youngest Top 50 member, hit 10 double faults against Ivanovic, but was greatly helped by Ivanovic's 56 unforced errors. In the deciding set, however, Ivanovic reduced the number of errors, from 21 and 22 in the first to sets, to 13, and her winners-UE differential improved from -8 in the first and second set, to -3 in the third, while Stephens converted just one out of seven break points in that third set and hit six double faults.

Ivanovic's opponent in the fourth round will be Tsvetana Pironkova, and although they are tied at 1-1 in head-to-head, their last meeting was before the 2008 French Open. Pironkova is best known for her 2010 Wimbledon semifinal, when she became the first Bulgarian, male or female, to play a Grand Slam semifinal.

The Bulgarian, who turned pro in 2002, is a hilarious character. Do you know that only last year she realized that ranking points are awarded at all WTA tournaments and not just Grand Slams? 

I've been a pro for a while, but I must have missed that memo. I go to some of those tournaments, of course, but–unless I get the urge to upset one of the big stars–I like to leave early. The practice, the locker room chaos, the crowds–it can be so dreary.

Plus, she actually loves the rain at Wimbledon, because she loves water and her father was a canoe champion and mother a swimming champion:

The problem I have with tennis courts, is that they're dry. That's why I like Wimbledon; there's usually a lot of rain, and I can splash around like I do at home.

So, who's your pick, Ivanovic or Pironkova? I believe in Ivanovic! (photos: © Neal Trousdale)

As expected, we enjoyed the concurrent Grand Slam sort-of success of the Serbian sisters for a short time. Second seed Agnieszka Radwanska was a big obstacle for Jelena Jankovic this time, even though the Pole is past the second round at the US Open for the first time in four years, while even before that her results couldn’t match Jankovic’s semis here in 2006, quarterfinals in 2007 and final in 2008. Those days are long gone, though, and today Radwanska converted six of seven break opportunities to eliminate the former world No.1 in straight sets, 6-3 7-5. Let’s see what Ana Ivanovic will do tonight against Sloane Stephens. Read more »