Top-ranked Victoria Azarenka extended her winning streak to 24 matches with a 6-3 7-5 victory over Michaella Krajicek in the second round at the Sony Ericsson Open.

Azarenka’s streak began with her first match this year and her start is the best since Martina Hingis went 37-0 to begin 1997.

Azarenka is bidding for her third Miami title and second in a row.

She double-faulted six times and lost three service games, but Krajicek was even more erratic with her serve.

The Dutchwoman failed to hold at 5-4 in the second set, double-faulting three times, and Azarenka swept the final 10 points.

The Belarusian is seeking her fifth title this year.

Serbian 15th seed Ana Ivanovic beat American Vania King 6-4 7-5 in her first match since retiring with a left hip injury a week ago at the Indian Wells semi-finals.

Two wildcards eliminated seeded women.

Garbine Muguruza Blanco of Spain upset Russian ninth seed Vera Zvonareva 6-4 6-3, and Aleksandra Wozniak of Canada rallied past Romanian Monica Niculescu 4-6 6-3 6-4.

On the men’s side, fourth seed Andy Murray won his opening match by beating Alejandro Falla 6-2 6-3.

Murray, the 2009 champion, bounced back from a loss in his first match at Indian Wells two weeks ago. He also avoided a repeat of last year, when he lost his opening match at both Indian Wells and Miami.

With the victory, Murray improved to 15-3 this year.

Other seeded men to reach the third round included French sixth seed Jo-Wilfried Tsonga, Serbian ninth seed Janko Tipsarevic and French 13th seed Gilles Simon.