Five-time champion Serena Williams enjoyed a convincing win in the third round of the Australian Open on Saturday, but there were tears as two of the top 10 seeds departed after major upsets. Williams thrashed world number 92 Greta Arn 6-1, 6-1 in 59 minutes to close out the women\'s third round in an ominous display as she seeks her 14th grand slam win. She will now take on Ekaterina Makarova in the round of 16 following the unseeded Russian\'s surprise 7-6 (9/7), 6-1 win over seventh seed Vera Zvonareva. Zvonareva left the Australian Open in tears after her loss to 56th-ranked Makarova, while China\'s Zheng Jie also caused an upset as she sent ninth-seeded Frenchwoman Marion Bartoli crashing out 6-3, 6-3. Wimbledon champion Petra Kvitova and Russia\'s Maria Sharapova, the 2008 Australian champion, sailed through their matches. Kvitova won 6-0, 1-0 when Russia\'s Maria Kirilenko retired with a thigh injury, while Sharapova beat feisty German Angelique Kerber 6-1, 6-2. The 32-year-old Arn started well against Williams in the Rod Laver Arena and had a break point in the opening game, but that was as close as she got as the American stepped up to overpower her opponent and run away with the match. Williams broke Arn twice in the first set and three times in the second as the Hungarian wilted on the big stage. \"I\'m nowhere near where I want to be, but I\'m trying to play through it,\" said Williams, who missed much of last year with injury. Zheng got away to a lightning start against the powerful Bartoli and there was no let-up in her raking ground strokes as she joined fellow Chinese Li Na in the fourth round, where she plays Italian Sara Errani. Wimbledon title-holder Kvitova also showed tremendous power before Kirilenko retired injured in the second set. After breaking Kirilenko\'s serve in a 10-minute opening game, the Czech world number two raced through the remainder of the set with a succession of booming serves and punishing ground strokes. \"The way I played in the first five games was great,\" she said. \"I mean from the last match that I played it was really a big difference and I\'m really happy how I played today. Hopefully it will continue like this.\" Kvitova will play Ana Ivanovic in the fourth round after the Serb\'s 6-4, 6-4 win over American Vania King, while Italy\'s Errani downed Romanian Sorana Cirstea 6-7 (6-8), 6-0, 6-2. Sharapova was flattered by the scoreline in her match against the 30th seeded Kerber. The Russian number one, who won in Melbourne in 2008, broke Kerber three times in each set but had to battle in the second as Kerber lifted her game. \"I played a really good first set but she certainly stepped up in the second,\" Sharapova said. She next plays 14th seeded German Sabine Lisicki, who ended the tournament of two-time grand slam champion Svetlana Kuznetsova 2-6, 6-4, 6-2.