Serena Williams  vs
Samantha Stosur (AUS)  vs Garbine Muguruza (ESP)  . These two have only played once before, but it was on clay (in Madrid), and Stosur won that match 6-1 in the third. Muguruza's ascension to the #3 ranking in the World after her dreamlike run to the Wimbledon final was not unexpected, but it was surprising that it happened on grass and not a hard court. But the Venezuelan-born 22-year-old who plays for Spain and has trained on clay in her formative years was always expected to be competing for majors and the #1 ranking at some point and it looks like those days have arrived. The 32-year-old Australian has had excellent success in Paris, having reached the semifinals four times in her career (1-2 record) but there is a reason why Muguruza is seeded #4 compared to Stosur's #21 at this year's tournament. Even though Stosur is a 2-time major finalist, she is not as mentally tough as her opponent, as their different WTA tour final records (Stosur is 8W-15L while Muguruza is 2W-3L) reflect. I believe that will be the difference that leads the young Spaniard to her second major final in as many years. MadProfessah's prediction: Muguruza.