The first semifinal pit Maria Sharapova and Victoria Azarenka in a match where No.2 was on the line.
If Azarenka won, she would return to No.2. If Sharapova defends her title here, she will stay No.2.
Sharapova was first to strike, getting broken off the bat but then cruising in the first set, 6-1.
But Azarenka started putting Sharapova on the defensive in the second set, taking that one, 6-2.
At the end of the second set there was a half hour rain delay - would that stop Azarenka's momentum?
The answer is yes. Sharapova broke away from 2-all in the second set to build a 5-2 third set lead.
Sharapova had her first four match points while serving in that 5-2 game, but not so fast...
Azarenka wasn't done - Sharapova missed three backhands and a forehand on those four match points.
But Sharapova would serve it out at 5-4, finishing off the 61 26 64 victory with an ace up the T.
The second semifinal pit Serena Williams and her 29-match winning streak against Sara Errani.
And Williams wasn't about to let the streak end, storming through the first set on Errani, 6-0.
Errani mustered up a game in the second set but in the end that was her only mark on the scoreboard.
Williams routed Errani in 46 minutes, 60 61, hitting 40 winners to just 12 unforced in the match.
Errani had just beaten her first Top 5 player in the quarterfinals, but that was the World No.4.
Williams, the World No.1, moved through to her 20th Grand Slam final - she has a huge 15-4 record.