In a dramatic performance Saturday night Israel's Shahar Pe'er (18 seed) beat Czech Nicole Vaidisova (13) 6:4, 3:6 7:6 (5) to make the fourth round of the US Open for the second year in row. Pe'er will play Agnieszka Radwanska (30), the surprising 18-year-old Pole who ousted second seed and defending champion Maria Sherapova on Saturday. Vaidisova stormed the court at the outset, breaking the Israeli's serve in the first game and rushing to a 3-0 lead. Pe'er, however, would not give up, breaking Viadisova's serve en route to a 3-3 and 4-4 tie. After breaking again to set the score at 5-4, Pe'er held serve to cap off a 6:4 victory in the first set. The second set opened almost exactly like the first one, with Pe'er lagging behind 0-3 before breaking her opponent's serve to equalize at 3-3. This time, however, Pe'er's comeback was left in the lurch when in the eighth game Viadisova broke her serve and held her own, taking advantage of a missed set point by the Israeli to win 6:3. The third set opened with two breaks (1:1) after which the two opponents each held serve to make it a 4:3 Pe'er lead. In the eighth game Pe'er broke the Czech's serve but Viadisova came back strong in the ninth and tenth games to equalize at 5-5. Pe'er then missed two match points, sending the third set into a tiebraker, where despite a number of missed match points she eventually prevailed 7:5, prompting a blaring rendition of "Hava Nagila" on the stadium's PA system.