Sharapova, who is one of the favorites, has never won in Miami.
“It would be special to win this and add it to my collection,” she said.
Sharapova advances to the quarter-finals, where she will face eighth-seeded Sara Errani, who rallied to beat former world No. 1 Ana Ivanovic 1-6, 6-4, 6-2.
Also, defending champ Agnieszka Radwanska defeated Sloane Stephens 4-6, 6-2, 6-0 to book a quarter-final clash with Belgian Kirsten Flipkens.
In the women’s doubles, Taiwan’s Hsieh Su-wei and China’s Peng Shuai lost to Russia’s Svetlana Kuznetsova and Flavia Pennetta of Italy 6-2, 6-2.
Additional reporting by staff writer