Maria Sharapova, Jelena Jankovic lost in Australian Open fourth round MELBOURNE, Jan. 20 (UPI) -- Fourth-round upsets Monday dropped former No. 1-ranked Maria Sharapova and Jelena Jankovic from the Australian Open. Dominika Cibulkova, the No. 20 seed, took out Sharapova 3-6, 6-4, 6-1. After Sharapova used three breaks to win the first set, Cibulkova jumped out to a 5-0 lead in the second, was in control throughout the third set and claimed her first quarterfinal berth at the Open. Sharapova, who entered the tournament as the No. 3 seed, hampered her own efforts with eight double faults among 45 unforced errors -- 34 of which came in the last two sets. 11-seeded Simona Halep gained her first quarterfinal in any Grand Slam event with a 6-4, 2-6, 6-0 decision over Jankovic, the No. After Jankovic evened the match with a three-break second set, Halep opened the third set by taking a long game, which seemed to spur her to finish strong. She won 31 of the 45 points in the set. 2-ranked and two-time defending champion Victoria Azarenka defeated 13th-seeded Sloane Stephens 6-3, 6-2 and fifth-seeded Agnieszka Radwanska took out unseeded Garbine Muguruza 6-1, 6-3. Azarenka allowed Stephens just two break chances and saved them both. She won nearly half (32-of-65) of the points off Stephens' serve and was 3-of-14 in break opportunities. The fourth round was completed with Radwanska's win over Muguruza. The match got off to a sluggish start but once Radwanska notched her first break -- she finished with four -- she moved quickly to the win. Muguruza, who was 0-for-6 in break chances, had 44 unforced errors to account for more than half of the 76 points Radwanska won. With No. 1-ranked Serena Williams, Sharapova and Jankovic falling in the past two days, only three of the women's top eight seeds have reached the quarterfinals in Melbourne. 4-seeded Li Na takes on 28th-seed Flavia Pennetta and No. 14 Ana Ivanovic plays 30th-seeded Eugenie Bouchard in the top of the draw. Halep meets Cibulkova and Azarenka goes against Radwanska in the other quarterfinal pairings.