If Serena Williams and Petra Kvitova can secure fourth-round victories on Monday, they would move closer to a blockbuster semifinal at Roland Garros. While Serena faces a familiar foe in a fellow American, Kvitova must contend with one of the WTA’s most successful players during the first few months of the season.

Serena Williams vs. Sloane Stephens

As players age and new ones emerge, there comes the inevitable talk about the changing of the guard or the passing of the torch.  When Sloane Stephens shocked Serena Williams in the quarterfinals of the 2013 Australian Open, there was immediate talk about the proverbial passing of the torch.  Williams has emphatically shut down such talk since that defeat, but come Monday, Stephens will have the opportunity to try and once again make that a topic of conversation.

It is easy to see why many people still believe Stephens could be the heir apparent to the Williams sisters in spite of the sophomore slump she suffered after a breakthrough 2013 season.  She has many physical gifts, chief among them being her power and foot speed.  She is capable of going big off both wings, as well as the serve, and little by little, she is becoming more comfortable at the net.  Most importantly, she appears to be increasingly willing to be the aggressor.  Stephens has to be aggressive in her upcoming match with Williams.  That equates to teeing off on second-serve returns, attacking any short balls, and ripping the ball up the line when the opportunity arises.  Her ability to retrieve may initially frustrate Williams, who has been slow out of the gate her last couple of matches, but it will not plant seeds of doubt in her mind.  Successfully and readily taking the initiative will.

But consistently capitalizing on her chances will in no way guarantee a victory for the younger American.  Williams is still the better overall player.  She boasts more power off the ground, and her serve is undeniably a more formidable weapon than that of Stephens.  Additionally, she is still one of the quickest players around the court and among the best at turning defense into the offense with a single stroke.  Williams needs to be patient in this encounter, though.  As Stephens showed in her opening match against Venus Williams, she does an exceptional job of making opponents hit one more extra ball.  Williams can ill afford to press and be goaded into easy errors.  Instead, she should remember that as long as she is able to get Stephens on the run, she need merely wait for the short ball and then go on the attack.

Williams is apt to be plenty eager to go on the offensive in this match, too.  She took that Australian Open loss two years ago pretty personally, and she has made Stephens pay ever since.  She has won the three times that they have met since then, including twice this year.  In fact, she absolutely demolished Stephens when they met a few weeks ago in Madrid, giving up just a scant four games in that encounter.  Add that to all of the experience she has playing on a Grand Slam stage, and Stephens is facing an uphill battle. 

Stephens will not be completely without belief in this match, however.  She does have that one victory off Williams, and when the two met earlier this year at Indian Wells, their match went the full three sets.  Furthermore, Stephens lists clay as her favorite surface, and this does seem to be a venue where she typically produces some of her best tennis.  If Williams gets off to another slow start, this is as likely a spot as any for Stephens to make her pay.

Stephens has put herself in the best position possible to get the win over Williams and add to the list of upsets that have already transpired at this year's Roland Garros.  The odds do not favor that upset occurring, and if Williams brings her A-game, it will not.  But if she brings anything less, Stephens, as she has already proven once, has the goods to get the better of Williams and to get people once again talking about a potential changing of the guard.

Petra Kvitova vs. Timea Bacsinszky

Many seeds have already lost at Roland Garros this year, but some of the top ones still remain, among them Petra Kvitova.  Many analysts picked the Czech as an outside favorite behind Serena Williams and Maria Sharapova to take the title here in Paris, but if she hopes to validate the faith they have shown in her, she will need to first get through Switzerland's Timea Bacsinszky on Monday.

Bacsinszky is certainly not the first name who comes to mind when thinking of Swiss tennis.  She struggled through a plethora of foot and ankle injuries that kept her mainly relegated to the sidelines in 2011-2013, but she has done well throughout 2014 and into this season to carve out a space for herself in the game.  She bagged titles in Acapulco and Monterrey this year, as well as reaching the finals of Shenzhen, the quarterfinals of Indian Wells, and a round of 16 finish in Rome.  She is presently ranked a very respectable No. 24 and looking to climb even higher.

Kvitova is another player looking to ascend the rankings with a good result at Roland Garros.  She has worked her way back to No. 4, but with her talent and gifts, there are many who believe she has what it takes to get to No. 1.  She is a two-time Wimbledon champion and picked up a couple more titles this year with her efforts in Sydney and Madrid.  She backed up that Madrid result with a quarterfinal appearance in Rome and remains the only player this season to have dealt a loss to Williams.  No doubt she would like to continue her run of good fortune by winning her first title here in Paris.

Kvitova will be the one more in control of whether or not her stay in Paris will continue following her match with Bacsinszky.  Both women list the serve among their favorite shots, but lefty Kvitova's has more pop and direction.  She also has easy power from the ground and is among the top two or three biggest hitters in the game.  In addition to that, Kvitova possesses nice feel on the drop shot and at the net, both of which are tough to counteract for an opponent who spends the majority of the match fending off bludgeoning blows from the Czech.  There are not many areas where Bacsinszky can hope to gain the upper hand, but there are perhaps two categories where she might fare slightly better than her high-ranked opponent.  The Swiss is a bit quicker at covering the court on defense, and she can be more consistent, which could come into play if Kvitova is having a bad day at the office.

On paper, the fourth seed should be the less likely of the pair to allow the occasion to get her.  She has the two Wimbledon titles, has been to the semifinals of this event, and has far more experience on a Grand Slam stage.  Contrast that with Bacsinszky, who prior to this tournament had never been out of the second round of Roland Garros and never to the second week of any of the majors.  But the Swiss is the underdog in this match, so the pressure is squarely on her opponent's shoulders.  Furthermore, it is imperative that Bacsinszky always mentally stay in this match and force Kvitova to play, even if she gets in a hole early.  The reason for this is that for all her experience and accomplishments, Monday's battle will mark the first time since 2012 that the Czech has contested a match in the second week of a major outside Wimbledon.  Additionally, she looked shaky in Week 1, can be erratic over the course of a single match, and it was Kvitova who came out on the losing end of their only other meeting, which came in Shenzhen this past January.  So, if Bacsinszky hangs tough, Kvitova could give her some errors and possibly a path to the quarterfinals.

There is no telling how this match will unfold.  It could be tight and entertaining, or it could be a blowout.  It depends on how each woman handles the moment, and more importantly, which Kvitova show up to play.  If everything in her arsenal is clicking, she gets through to the quarterfinals.  If not, the breakthrough run for the Swiss may continue.