The last two US Open finals have pitted Serena Williams and Victoria Azarenka. They could meet in a semifinal there this year if each can solve their opponents on Wednesday. But that may not be as straightforward as it looks.

Serena Williams versus Flavia Pennetta

Most commentators are in agreement that Serena Williams has been given a green light to secure her 18th major singles title.  Next up, she takes on Flavia Pennetta, and the Italian will be looking to do everything possible to derail the American’s bid for the title.

Truth be told, Pennetta finding a way to defeat Williams is a very tall task, and she knows it.  Pennetta has faced the current world No. 1 on five occasions and lost on every one of them, including a US Open quarterfinal clash five years ago.  Only one of their previous encounters has gone the distance, and that was their first meeting back in 2008.  Mentally, that is a track record that is going to be hard to overcome when she takes on Williams for a sixth time on Wednesday.

It is hard to see strategically what Pennetta can do to make Williams think that this match will be any different than in years past.  Williams has the superior firepower on both serve and groundstrokes, and she is also a better mover.  Equally important, she has far more experience playing at this stage of a major.  If there is one area where Pennetta has Williams beat, though, it is with her net skills.  She is a former No. 1 in doubles, so if she can get to the forecourt and rush Williams, she is in with a chance.  The problem for the Italian will be finding a way to get to the net with any kind of frequency given how hard Williams hits the ball.

One intangible that may help Pennetta’s cause, however, is how well Williams psychologically handles this match.  Pennetta is not exactly known for being the most mentally tough player out there, but it is Williams who has more to play for and more pressure on her shoulders.  The American got a bit of a monkey off her back just by reaching the quarterfinals, a feat she surprisingly failed to achieve at the year’s first three majors.  But she desperately wants that 18th Grand Slam singles title, and wanting it too badly could have a negative impact on her game.  In addition to that, with so many of her primary threats already out of the tournament, expectations may feel even greater on Williams to take advantage of the situation.

When all is said and done, odds do favor Williams getting through this encounter and likely the remainder of the tournament.  But Pennetta is a fighter, and she will undoubtedly utilize everything at her disposal to try and get the victory. 

Victoria Azarenka versus Ekaterina Makarova

It may not be No. 1 versus No. 2, but of the four quarterfinals, Victoria Azarenka coming up against Ekaterina Makarova is as even as they get.  Separated by one place in the rankings and seeded just one spot apart, this is a quarterfinal clash that could come right down to the wire.

Historically, past matches between this duo have been close.  Azarenka holds the edge over Makarova 3-2, but most have been relatively tight affairs.  It is Makarova who enters this latest installment in their rivalry having won their last encounter in Madrid last season, but Azarenka has won both of their matches on the hard courts.  Azarenka will have to be at her best, however, if she hopes to grab a third victory on this surface against the Russian.

A big part of the reason why Azarenka needs to look sharp is that in most areas, Makarova can match her shot for shot.  Azarenka possibly hits a little harder off the ground, but the No. 18 seed is perfectly capable of smacking her share of winners from all corners of the court and is the better mover.  She also has the added advantage of being a lefty and is more accomplished in the forecourt.  Additionally, like Azarenka, Makarova enjoys the hard courts, so she will enter this clash confident in the knowledge that she has the requisite skill set to hang with the former No. 1.

Confidence in the knowledge that she can defeat Azarenka does not necessarily equate to Makarova successfully managing the situation, however.  The Russian has been to a few major quarterfinals, but she has yet to advance to the final four.  She has an excellent shot against a rusty Azarenka of achieving that milestone for the first time in her career, but whether or not her nerves will hold up down the stretch is debatable.  \

Of course, the same could be said for the Belarusian.  Considering how little she has been able to play in 2014, Azarenka has already put in a solid effort to get to this stage, particularly in her comeback victory against the crafty qualifier Aleksandra Krunic.  Her current run is all the more admirable considering she has the added pressure of defending finalist points from last year.  Then again, given her injuries this season, she probably entered this US Open with low expectations.  If that is the case, she may be swinging more freely than Makarova, which could prove crucial as this match draws towards a conclusion.

This contest should be as even as it appears on paper.  Whether or not the match ultimately plays out that way remains to be seen, but it definitely has all the necessary ingredients to be one of the better quarterfinals.  It all comes down to who is most willing to step up to the plate and take this match rather than wait for the other to lose it.