The world's top two came through their respective semis in straight sets on Saturday.
Williams, the current world number one, beat Sara Errani 7-5 6-2 and will be aiming to claim her 50th WTA title on Sunday. If she does so, she will keep her top spot in the ranking list.
The American twice fought back from a break down to win a closely contested opening set before dominating the second to see off the seventh-seeded Italian.
"I guess I'm a little happy," she told www.stator.com.
"I feel that I played solid. In the second set more than the first I made less errors, which was something that I really needed to do today [Saturday]."
Second seed Sharapova was a 6-4 6-3 winner over Serbia's Ana Ivanovic, edging a tight first set and then coming back from a break down in the second.
It was the Russian's 500th career win.
"That number is pretty significant," she said. "I'm pretty proud of that."
The Russian has a poor record against Williams, winning just two of their 14 encounters and with her last victory over the American back in 2004.
However, Sharapova is up for the challenge and said: "It's always tough against her.
"I haven't had a win against her in a long time, but the great thing is I'm setting myself up in a position where I can try to change that around."