Venus Williams versus Carla Suárez Navarro

The Williams Family has already had plenty to celebrate with Serena Williams giving birth to her first child on Friday, and Venus Williams will be looking to add to the family's joy by securing her third US Open singles title.  She will be favored to keep those title hopes alive when she takes to the court against Carla Suárez Navarro, but she is not a lock.  Williams only holds a slight edge in their rivalry 4-3 and 2-1 at the majors.  Two of the Spaniard's three wins have come on the hard courts as well, so she will not be lacking in belief when she takes on the ninth seed.  That said, she will be made to work harder if she wants to the garner the upset. 

She must create space to produce winners, but she is plenty capable of finding the requisite angles, particularly with her sweeping, one-handed backhand.  She is also going to need to continually give Williams different looks at the ball and come with her running shoes on to test the consistency of the American.  Even all of that may not be enough, however.  Williams stands nearly a foot taller than Suárez Navarro, which gives her an advantage on serve and in covering the net.  Her exceptional court coverage will also make it difficult for the Spaniard to find openings and weaknesses, and there is no denying that she boasts far more firepower in every aspect of her game.  In short, if Williams plays her A-game, she advances.  If not, then an upset is not out of the realm of possibility.

Garbiñe Muguruza versus Petra Kvitova

A battle of major champions will be on offer in this fourth-round clash that pits Garbiñe Muguruza against Petra Kvitova with a berth in the elite eight hanging in the balance.  If both are at their best, this match will come down to the smallest of margins, as there is little to choose between the pair.  They are two of the most powerful shot-makers in the sport, able to produce spectacular winners from either wing and from anywhere on the court.  Each also has a booming serve and is competent in the forecourt. The Czech arguably has a slight edge on serve due to being a lefty, and when firing on all cylinders has a little more feel, especially at the net.  It is Muguruza, however, who enjoys the advantage in the movement department. 

More importantly for the third seed, she should be significantly more confident than Kvitova, despite having lost her last two meetings against the Czech.  Muguruza is having a great summer, having reigned victorious on the lawns of Wimbledon and securing the title in Cincinnati before arriving in New York.  She was the popular pick among many to take the title here, and that status will not change against Kvitova, who is still shaking off the rust after missing most of the first half of 2017.  So, while the Czech definitely has the weapons to upend Muguruza, the Spaniard's form is too good for her not to be considered the clear favorite in this contest.

Pablo Carreno Busta versus Denis Shapovalov

With each passing round, the bottom half of the men's draw becomes increasingly wide open.  Two of the competitor’s eager to take advantage of that are Pablo Carreno Busta and Denis Shapovalov, though only one of them will still have the chance to do so by the time play ends on Sunday.  At the moment, many are probably looking to Shapovalov as the man to advance despite his lack of experience not only at the majors, but on the tour level as a whole.  But there is no timetable for when a player will announce his arrival to the sport, and the teenager has backed up his phenomenal run in Canada with such a strong showing here.  He plays a fearless brand of power tennis, able to rip winners from either wing and on serve. 

He is constantly looking to go on the offense, and as evidenced by his victories over Juan Martin del Potro and Rafael Nadal in Canada, he has the tools to dictate to even the sport's greatest.  He will unquestionably be looking to do the same to Carreno Busta, but folks should not be looking past the Spaniard.  He has quietly risen into the Top 20 and is a solid, all-around player.  He can really lean on his backhand to procure winners, his forehand is no slouch, and he is better at the net than Shapovalov.  He knows how to work a point, and though he has not been here regularly, he has been to this stage of a major and beyond before.  The question will be whether the Canadian's flashy and scintillating tennis or the Spaniard's rock solid and steady approach will prevail.  It will depend on how high of a level Shapovalov can maintain, and if he can do so consistently, he will earn another upset.  Based on his form throughout this summer, that looks likely to be the case.