Top seed Serena Williams cruised past Agnieszka Radwanska 6-0, 6-4 to reach the final.
Williams' form dipped slightly in the second set, allowing Radwanska to win three straight games.
But the defending champion did not leave her many other chances, breaking again and converting the first match point after three straight aces.
Williams says her opponent recovered from a bagel set but so did she to hold her off.
"I was really hitting just all the right shots, making little to no errors, which is kind of hard to play like that. But it was good. She started playing better. It was good for me mentally as well because I was able to recover and do well again."
Williams has 21 Grand Slam titles under her belt, only one short of Steffi Graf's record.
She will have to get past Angelique Kerber first if she is to match that record.
Kerber ended darkhorse Joanna Konta's run 7-5, 6-2 to reach the final.
In men's action,
Novak Djokovic got past Roger Federer in four sets to reach a 17th straight Grand Slam final.
The world number one set a blistering pace at the beginning of the match, winning the first two sets 6-1, 6-2.
Federer recovered to take the next set 6-3 but couldn't keep up with the level to lose the last set 6-3.
The winner of the match between Andy Murray and Milos Raonic tomorrow will be the other finalist.
And in men's doubles,
It is Andy Murray's brother Jamie and Bruno Soares making it into the final in straight sets 6-3, 6-1.