Before Serena Williams continues her quest for a calendar Grand Slam against a familiar foe, two less heralded names aim to move within one win of their first major title. One is a former Wimbledon finalist, while the other never has reached the second weekend at any major.

Garbiñe Muguruza vs. Agnieszka Radwanska

The bottom half of the women's draw has been riddled with upsets.  Top seed after top seed has tumbled out to a premature exit.  But in their absence, two women, Agnieszka Radwanska and Garbiñe Muguruza, have risen as an unlikely pair of semifinalists.  They have done well to take advantage of their situation thus far, and come Thursday, one of them will have continued to cash in on her good fortune by booking a place in the Wimbledon final.

Given that these two women have evenly split their previous four meetings, it could be said that each has a fair look at earning the win on this occasion.  Both should also be feeling relatively confident about their odds of advancing, albeit for different reasons.  In the case of Muguruza, she has had the more difficult journey, but in turn, she has also garnered a couple more impressive victories to reach the final four, which should give her added confidence.  In addition to that, the Spaniard is physically more imposing than Radwanska.  She exhibits greater power from the ground, is decent on the volley, and holds a clear edge with her serve.  Assuming she has a good serving day and is able to consistently hammer away from the ground to keep the Pole pinned behind the baseline, Muguruza will be the player in the more favorable position to control the majority of what is happening out on the court.

Radwanska is a smart player, however.  She is aware that she does not have anywhere near the same level of firepower as Muguruza, and while she will not be intimidated by the bigger-hitting Spaniard, she will certainly not look to simply trade groundstrokes with her either.  Instead, Radwanska must aim to put in a high percentage of first serves, continue making her regular forays to the net, and most importantly, utilize all the court craft and guile that once took her to No. 2 in the rankings.  The Pole has a lot of variety in her game and is able to make many opponents uncomfortable with the various spins and slices she puts on the ball.  It is essential that she use all of those tools in her bag of tricks and avoid getting pushed too far behind the baseline in order to keep Muguruza off balance and unable to tee off on her own shots.

Naturally, their ability to execute their respective game plans comes down in large part to who handles the magnitude of the moment best.  Here again, though, they are fairly evenly matched.  Unlike Muguruza, Radwanska is most at home on the grass.  She played brilliantly in the tune-up events leading into the Championships, and Wimbledon has been her most successful major.  She was a finalist here three years ago and is the higher-ranked of the pair.  The flip side of the coin in all of this is that since this is a breakthrough run, and she is the lower-ranked competitor, it is the Spaniard who has the luxury of being the underdog in this contest.  Furthermore, although their head-to-head is tied at two each, Muguruza has won their last two meetings, both of which came earlier this season.  Given her greater ability to control what transpires on court, Muguruza has to like her chances of making it three victories in a row.

Irrespective of which way this one pans out, it has been a noteworthy Wimbledon for both women.  They have admirably taken advantage of the way the draw has opened up, and there remains at least one more golden opportunity before them.  The question is, which of these women will snatch it and advance to the Wimbledon final?

Serena Williams vs. Maria Sharapova

There have been a number of upsets at this year's Championships, but Serena Williams and Maria Sharapova have not been among the victims.  The two highest seeds in the top half of the draw have fought their way to the final four to set up a marquee semifinal showdown.  On Thursday, they will clash for the 20th time with a coveted spot in the Wimbledon final hanging in the balance.

By now, it is no secret that this has been a rivalry dominated by Williams.  She has only lost two matches to the Russian, and they came more than a decade ago.  One of the main reasons Williams has enjoyed such overwhelming success is that this is a good match-up for her.  These are two competitors who employ similar playing styles, except Williams typically does everything a little bit better.

Williams and Sharapova both hit exceptionally big off the ground, but Williams has slightly more pop on her shots.  They both also have powerful first serves, yet here again, it is Williams who has more power and certainly has a more reliable second delivery.  Furthermore, the American is the better mover, is more secure up at the net, and has more margin for error on her groundstrokes.  That is a tough package for anyone to overcome, but Sharapova definitely has enough weapons to potentially put the top seed under pressure.  She will need to be at her best, though.  The current No. 4 will be the one having to take more chances to get on top in the rallies.  Additionally, she must have a good serving day, and in the end, will probably need at least a little help from Williams.

There is a decent chance that Sharapova will get that help she needs from Williams in their upcoming match.  While the American's tough draw has to be taken into consideration, there is no denying that Sharapova has looked the sharper of the two through the first five rounds here. Sharapova could also do a lot to help her own cause by maintaining a positive demeanor over the course of the entire match and keeping the proceedings close from the beginning.  It is true that the Russian is one of the fiercest fighters on tour, but Williams is the one opponent against whom she has at times exhibited body language that denotes timidity and even resignation. She has also on occasion pressed straight out of the gate against Williams, and as a result found herself in an early hole.  It is imperative that Sharapova avoid putting herself behind the eight-ball from the start.  After more than a decade of continually losing to the world No. 1, the last thing Sharapova wants is for both her and Williams to think that this match will inevitably evolve into yet another victory for the American.

That decade of dominance may be exactly what Williams mentally needs heading into this semifinal.  She knows what she is going to get from Sharapova and knows how successful she has been against her in the past, which should bring a certain level of comfort and confidence to the American.  Of course, nothing has really come easily for Williams thus far in the tournament.  She could have been dismissed in the third round by Heather Watson and was pushed hard by Victoria Azarenka in the quarterfinals.  Between those two matches and having to play her sister Venus Williams in the fourth round, she has also been more emotionally taxed to this point than her upcoming opponent.  There is the increasing talk of whether or not Williams can pull off the rare feat of winning the calendar Grand Slam as well.  All in all, the top seed is the player being asked to live up to a higher level of expectations.

In the end, the edge has to go to Williams as the likely victor in this battle.  She is the superior player and has an impeccable record against the Russian that cannot be ignored.  That said, this one has a different feel to it than some of their more recent encounters.  Williams has a lot more riding on this match and is seemingly feeling the pressure of trying to keep her various streaks alive.  This could be Sharapova's best look in a while at securing a third win over Williams.  It just remains to be seen if she can take advantage of it.