The Premier Mandatory event in Toronto has seen the top two players in the world fall in the early rounds as Kim Clijsters retired from her match against Jie Zheng with an abdominal problem while top-ranked Caroline Wozniacki was not able to fend off an upset on Wednesday as Italy's Roberta Vinci pulled off the stunner.
However, the women's draw at WTA Toronto still features several top players, including French Open champion Na Li, Wimbledon champion Petra Kvitova, third-ranked Vera Zvonareva and No. 4 seed Victoria Azarenka.
One potential semifinal matchup that is brewing is a possible showdown between Serena Williams and Maria Sharapova.
Williams is unseeded in the draw and she has also been reasonably untroubled so far in the tournament. Through the first two rounds Williams is 4-0 in sets played, with only one of those sets being close as Germany's Julia Goerges took Williams to a tiebreaker in the second round.
Up next for Williams is Zheng, a player who can only be considered moderately threatening to the former world No. 1. Zheng is capable of playing at a high level as she has twice made the semifinals of a Grand Slam; however, she does not seem likely to trouble Williams on Thursday night from Toronto as Zheng does struggle with consistency.
Should Williams win that match she could face no one more dangerous than Francesca Schiavone, the 2010 French Open champion and eighth seed in Toronto. Schiavone has to be considered to be more dangerous to Williams than Zheng however the Italian has only been able to best Williams in the past on clay. On the hard court surface Williams is 4-0 against Schiavone in sets played.
Sharapova's course to a semifinal showdown with Williams looks challenging with the fourth seed in the way but the Russian has what looks to be an easy match coming up on Thursday. Sharapova will face Galina Voskoboeva in the third round, a player who is very inexperienced in WTA matches of this magnitude.
Voskoboeva did pull off a stunning victory when she defeated Marion Bartoli earlier in the Toronto draw however you have to wonder if the Kazakhstan national can keep pulling off the upsets. She started the WTA season ranked outside of the top 500 and she has losses this season to players that many of even the most dedicated WTA fans probably have never heard of, players like Nastja Kolar, Mervana Jugic-Salkic, Kumiko Iljima, Iryna Bremond, Jennifer Elie and Valeria Solovieva.
It's fair to say that Voskoboeva, who was once a top-70 player, has improved during the course of 2011. In fact, she has improved quite drastically if she's dispatching the likes of Bartoli and Flavia Pennetta. However, Sharapova is a cut above those players and she'll be looking to fend off an upset on Thursday.
Sharapova will face a true test in the quarters if she faces Victoria Azarenka and it's fair to say that either of those two players could advance to the semifinals as they are both accomplished at the Premier Mandatory level.
However all scenarios considered, a Williams vs Sharapova semifinal looks like the most probable scenario on their half of the draw and that is the matchup that the fans in both Toronto and around the world will be most interested in. Schiavone and Azarenka are the spoilers with Voskoboeva an eyebrow raiser following her two impressive wins already in Toronto.