The Russian will play Agnieszka Radwanska in Saturday's final after the Pole beat France's Marion Bartoli 6-4, 6-2 to reach the biggest final of her career.
Second seed Sharapova, who has lost in all three of her previous finals in Miami, will start as clear favorite after another solid showing against Wozniacki.
The Russian was ahead early but lost the first set after her serve disappeared, allowing Wozniacki to win five consecutive games and take command of the match.
But the Russian recovered in the second set, striking the ball with impressive power.
"I could have easily, after losing a few straight games, let concentration down, I could have easily just gone down in the second set," said Sharapova.
"But I really stepped it up again. I went out there and started being aggressive. I didn't stop after I put myself in a good position. I'm extremely pleased that I pulled it out today." Wozniacki stuck at her task however and with Sharapova serving for the match at 5-3 she broke, forcing two errors out of the Russian after winning a rally with a magnificent backhand cross-court winner.
The Dane held serve and then faced Sharapova serving for the match again.
There was a controversial finish when Sharapova's serve at 40-15 was initially ruled out but the call was overruled by the chair umpire, who ordered the point to be replayed.
Wozniacki, whose return had found the net, protested the decision but with no challenges remaining she was stuck with the verdict and Sharapova subsequently wrapped up the win with a smart volley.
"Overall I'm pretty happy with my game," said Wozniacki, who beat Serena Williams in the quarterfinals. "This week I have been playing some really good tennis. And obviously you love to win and I didn't do that today." Radwanska dominated from the outset against a determined Bartoli and took advantage of the 35 unforced errors from her French opponent.
The Pole was well set at 4-2 in the second set when the lights went out on stadium court and there was a 20-minute delay before play resumed and Radwanksa booked her place in the final.
Sharapova has won seven of the eight previous meetings with Radwanska.
