( CNN ) -- Women 's world number one Victoria Azarenka is through to the third round of the Miami Masters , extending her winning run in 2012 to 24 matches after beating Michaella Krajicek of the Netherlands in straight sets . Azarenka has already won four tournaments in an astonishing start to the year and the Belarusian was expected to brush past her 71st-ranked opponent . But Krajicek had other ideas , battling all the way before Azarenka 's superior quality finally told in a 6-3 7-5 victory that took one hour and 42 minutes . However , there were plenty of shock results elsewhere in the women 's draw , with ninth seed Vera Zvonareva the biggest casualty , the Russian going down 6-4 6-3 to Spanish wild card Garbine Muguruza Blanco . Also departing the tournament are 18th seed Angelique Kerber , Lucie Safarova ( 27 ) , Kaia Kanepi ( 31 ) and Nadia Petrova ( 32 ) , who all lost in straight sets , while Monica Niculescu ( 28 ) was beaten in three . But 15th seed Ana Ivanovic is through after seeing off American Vania King 6-4 7-5 , while fifth seed Agnieszka Radwanska , 16th seed Dominika Cibulkova and 22nd seed Maria Kirilenko also advanced in straight sets . They were joined in the last 32 by Italian Flavia Pennetta , but the 24th seed was taken to three sets by Lourdes Dominguez Lino of Spain before prevailing . Meanwhile , in the men 's draw , fourth seed Andy Murray secured his place in the last 32 with a routine 6-2 6-3 win over Alejandro Falla . The Briton 's 76-minute victory ended a losing run on the Florida hardcourts which had seen him beaten in his opening matches in both 2010 and 2011 . There were also straight sets win for seeds Jo-Wilfried Tsonga ( 6 ) , Janko Tipsarevic ( 9 ) , Gilles Simon ( 13 ) , Alexander Dolgopolov ( 18 ) , Florian Mayer ( 19 ) and Philipp Kohlschreiber ( 32 ) , while 22nd-seeded Austrian Jurgen Melzer went through in three sets .
Women 's No.1 Victoria Azarenka moves through to the third round of the Miami Masters . Azarenka beats Michaella Krajicek in straight sets to win her 24th match in a row in 2012 . Andy Murray , Jo-Wilfried Tsonga and Janko Tipsarevic all go through in the men 's section .