The first womens semi final is between two naturalised Americans, Monica Seles and Martina Navratilova, and it is on clay (as both played on the hard and grass in the QF stage).
Monica has 9 grand slam titles and 4 RU spots. She played in 3 French Open finals and won 2 of those, in 1990 and 91. Her overall win loss record in Paris was 54 - 8 so around 87% which is very strong and makes this her strongest surface possibly.
Martina won 18 grand slams out of 32 finals. In Paris she won 2 finals, as per Monica, and was RU 4 times. Her Clay record overall was 51-11 in Paris, so very similar to Monica, around 82% from a quick calculation.
And these two have a head to head record - between 1989 and 1993 they played 16 times and Seles pipped it 9 wins to 7. All but 3 of those where in finals, but only 2 in slams, when Monica won both times. They never played on clay though!
This is incredibly tight set of records, I think that this could be a close one!
