Azarenka improved to 4-0 lifetime versus Casey Dellacqua with a 6-3, 6-1 victory. She's lost as many as three games in a set versus Dellacqua only once in the four matches.
Azarenka landed 75 percent of her first serves and won 26-of-36 points in those situations. She piled up five breaks while winning more than half (27-of-52) of the points when Dellacqua served.
Fifth-seeded Angelique Kerber defeated Anastasia Pavlyuchenkova 6-3, 4-3 when Pavlyuchenkova retired. Kerber had three breaks and was 5-for-5 in saving break points when the match was stopped when Pavlyuchenkova had a left leg injury.
The other two matches on Wednesday's schedule didn't even get to the court as Ashleigh Barty was unable to play due to a thigh injury, giving third-seeded Maria Sharapova a spot in the quarterfinals, and seventh-seeded Sabine Lisicki became ill and was unable to go against Stefanie Voegele.
That walkover put Voegele into the quarterfinals against Azarenka. The other third-round pairings are to be set Thursday.
Swim Week Miami Beach 2014 [PHOTOS]