Russian Sharapova reached her first final of the year in impressive style as she powered back from dropping the first set to beat Andrea Petkovic 3-6 6-0 6-2.
Germany's Petkovic had been the surprise of the tournament, with the 21st seed knocking out world number one Caroline Wozniacki in the fourth round and Jelena Jankovic in the quarter-finals.
She looked well set to add 16th seed Sharapova to her victims, but the 23-year-old had no answer to Sharapova's fightback.
Azarenka, the eighth seed from Belarus, was a remarkably easy 6-0 6-3 winner against third-seeded Russian Vera Zvonareva.
Assessing the threat posed by Azarenka, who won the Miami title in 2009, Sharapova said: "She plays really aggressive and swings really hard from both sides. She's a great returner. It'll be tough.
"I lost to her the last time we played in Stanford, so I'll look to change a few things around if I play her."
Azarenka won the Stanford match in straight sets last year, but they have each beaten the other twice in their four career meetings to date.
Sharapova won titles in Memphis and Strasbourg last year, and now has her eyes on one of the biggest prizes in women's tennis.
Asked what it would mean to triumph in this weekend's final, Sharapova said: "It would mean a lot. It's the biggest tournament I think after the grand slams.
"I look forward to going out there and getting it done.
"I feel like I'm finding my form."
Victory for the 16th seed over the 21st seed saw Sharapova avenge her defeat to Petkovic at the Australian Open.
Petkovic admitted she ran out of steam, with efforts in the previous rounds catching up with her.
"By the end of the second set I was getting frustrated with myself because I felt my energy slowly slipping away," she said.
"Of course I'm in a semi-final and I wanted to win this, so there was a little dialogue inside.
"You're like, 'Come on, you can win this', but your body is like, 'No, I don't want to'.
"I was fighting with myself inside.
"A champion like Maria, she just feels any kind of weakness, and she just played much, much better."
