Shahar Pe'er battled her way into the last 16 of the Sony Ericsson Open in Miami on Sunday by defeating Ukrainian Julia Vakulenko 7-6(5), 7-5 in a third round match that lasted an hour and 50 minutes. The Israeli, who is ranked No. 16 in the world and seeded 14th at the massive $3.45 million tournament, will next play the winner of the third round match between world No. 3 Svetlana Kuznetsova and Croatian Jelena Kostanic Tosic (98). Pe'er struggled with her serve throughout the match against Vakulenko (69) and was broken in the first game of the third round encounter. The Israeli immediately tied the score with a break of her own, but the 24-year-old Ukrainian took advantage of her opponent's weak serving and opened a 4-2 lead. Pe'er reeled off three straight games and served for the set in the 10th game, but she failed to hold her serve and the set had to be eventually decided by a tiebreaker. Six of the first eight points of the breaker were won by the Israeli teen and in the fourth time of asking, Pe'er clinched the set. The Israeli continued her good play at the start of the second set and took a quick 3-1 lead. However, the Ukrainian once more fought her way back to tie the score at 3-3. The players continued to exchange games as the set progressed, but Pe'er got a crucial break in the 11th game of the second set and wrapped up the match on her serve in the next game. Pe'er, who received a first round bye, booked her place in the third round after defeating Colombian Catalina Castano (76) 6-2, 6-1 in a rain-interrupted match Saturday night.