Second seed Sharapova disposed of home favourite Li Na 6-4 6-0 in the first semi before top seed Azarenka secured her place with a 6-4 6-2 win over Marion Bartoli.
Sharapova served three double faults to concede an early break to go 1-3 down in the first set against Li but sailed through once she found her groove.
She saved five of six break points and converted five of her own nine chances against seventh-seeded Chinese in a match that lasted an hour and 45 minutes.
"It was a really high quality first set with a few ups and downs, and obviously she had the lead in that set, but I came back," the Russian said.
"There were a few key moments to that set and after I broke her in the last game, it was important to take that momentum into the second set and keep going."
Sharapova, who lost in the quarter-finals of the Pan Pacific Open in Tokyo last week, was happy to be back in contention.
"I came into this tournament not playing extremely well in Tokyo, and I had a couple of days of practice here," she said.
"So I was hoping from the first round I'd really step it up and get better and I feel as the tournament has gone on I've been playing and moving better."
Sharapova, who served three aces while Li could not manage one, has now won eight of the pair's 12 meetings since 1995.
She won the first five only to see Li win the subsequent four before Sharapova's latest run of victories, which now stands at three.
Azarenka, who withdrew before her quarter-final in Tokyo due to health issues, showed no signs of trouble as she powered past Bartoli.
The Belarusian was clinical in breaking Bartoli six times, with just one break point wasted, while the ninth seed could only convert three of seven. Azarenka now has a 9-3 record against the Frenchwoman, who served six double faults.
Azarenka last won a title in March when she beat Sharapova in Indian Wells while the Russian is seeking her first trophy since winning the French Open in June.
Sharapova is looking for her fourth title of the year while world number one Azarenka seeks a fifth.
They have played four times in 2012, with Azarenka winning three of them including victories in the final of the Australian Open and the semi-finals of the US Open.
- Marion Bartoli