Rafael Nadal versus Dominic Thiem

The men's draw has been whittled down to eight, and not surprisingly, Rafael Nadal is among those still in title contention.  He has come through some tough battles to reach this point, and he will no doubt be prepared for another potential dogfight as he takes on Dominic Thiem for a place in the semifinals.  They are familiar rivals who have met ten times – all of them on clay – with Nadal leading the rivalry 7-3.  Like Nadal, Thiem has had to come through some tight matches to get here, and having successfully overcome those challenges could prove pivotal, as the outcome of this match could hinge more on how well Thiem reacts to the moment.  Nadal is certainly going to look to do what he does best, which is control the points with his forehand, rip the backhand, and shrink the court with his phenomenal defense.  Coupled with his improved serving and net play, he is a near-impossible hurdle for most opponents to overcome. 

But Thiem has already demonstrated his own set of weapons is enough to overcome the top seed, as he is one of only a handful of players to hand Nadal a defeat at least three times on his preferred surface of clay.  The Austrian boasts more power on his serve and tends go bigger off the ground.  That was on full display in his upset win over Kevin Anderson in the last round, against whom he had an even more dismal record.  The fact that he recognizes he needs to make a concerted effort to shorten his back swings and stay up on the baseline also bodes well for his chances.  If he can get his game firing on all cylinders as he did in the last round, then an upset is definitely in the cards.  But Thiem has never been to this stage of a major outside of Roland Garros, and it is going to be imperative that he hang with Nadal early and if possible, take the first set.  If he can do that, he is in with more than a decent chance.  If not, Nadal could steamroll him, much as he did in the final of Roland Garros earlier this spring.  One still has to like Nadal for the victory no matter what, but the top seed, and no one else for that matter, should be looking beyond this match just yet.

Karolina Pliskova versus Serena Williams

Revenge may be on the mind of Serena Williams when she takes to the court on Tuesday.  Two years ago, Karolina Pliskova defeated Williams in the semifinals of this tournament, becoming in the process one of only a select number of women to defeat both Williams Sisters in the same tournament.  Williams will be keen to turn the tables on this occasion.  Few would bet against her doing so.  Her serve remains the greatest in the women's game.  She is still one of the most powerful ball-strikers on the tour, and her ability to turn defense into offense is second to none.  She holds a decisive edge when it comes to defense in this particular match-up as well.  But Williams and savvy fans know that Pliskova can hardly be taken lightly. 

Although her own results since Wimbledon have been sub-par, she has still had a very solid season that has included a number of deep runs at the most prestigious events on the calendar.  She is one of the few women on tour who can compete with Williams as far as the first serve is concerned and is apt to strike her own share of aces in this match.  She can conjure easy power from either wing to produce flat groundstrokes that can keep Williams pinned to the baseline and on the move.  And though it is not often talked about in reference to the Czech, she actually has some nice feel in the forecourt.  If she has all facets of her game flowing in full flight, then she is more than a match for Williams.  Again, only a fool would bet against Williams, who has more experience and tends to be more consistent than the Czech at this juncture of a major but given Pliskova's history and status as a former Number 1, no one should be surprised by either woman emerging as the victor.

Juan Martin del Potro versus John Isner

In what is sure to be a raucous atmosphere, Juan Martin del Potro will take on John Isner for the right to move through to the semifinals.  Isner has ample reason to believe he can live up to the home crowd's hopes.  His serve is always a tool that gives opponents fits, and his forehand frequently allows him to dictate points and get to the net.  He has also stuck to his approach of being ultra-aggressive, understanding it may mean a few more errors, but also greater rewards, including a few more breaks that have helped him conserve energy by playing fewer tiebreaks.  It is an approach that has paid dividends for him this season, as he won the biggest title of his career this spring in Miami and went on to reach the semifinals of Wimbledon. 

That experience at Wimbledon could be just what he needs to get him over the hump in New York.  But del Potro will no doubt have other plans.  He has more experience playing in the latter stages of the majors, including reigning as champion here in 2009.  And while his serve may not be quite as big as the American's, it is still likely to earn him a number of free points.  His forehand is one of the biggest weapons in the sport, his return is superior as his movement, and his sliced backhand that can force Isner to get down low could be especially effective in this encounter. All of these factors have helped del Potro to a favorable 7-4 lead in this rivalry, and they could very well make it 8-4 by the time play ends on Tuesday.  A confident new-and-improved Isner is unquestionably in with a shot to garner the upset, but odds favor del Potro advancing at the American's expense.