Serena Williams upset at Australian Open
{{#rendered}} {{/rendered}}Error-prone American Serena Williams set loss to Ekaterina Makarova in the fourth round.
Williams, the No. 12 seed, hit 37 unforced errors and double-faulted seven times in her 82-minute match at Rod Laver Arena, falling to the 23-year-old Russian Makarova 6-2, 6-3.
Barely able to get her first serve in half the time, Williams hit 20 of her unforced errors and four of her double faults in the second set.
{{#rendered}} {{/rendered}}Earlier, No. 2 seed Petra Kvitova reached the quarterfinals of the season's first grand slam event with a straight-set win over Ana Ivanovic.
Kvitova, the 21-year-old Czech who beat Maria Sharapova to win Wimbledon last season, came through in a second-set tiebreaker to down the 21st-seeded Ivanovic 6-2, 7-6 (7-2).
The match, also Rod Laver Arena, lasted 85 minutes -- 54 of them for the second set.
{{#rendered}} {{/rendered}}Kvitova fired seven aces and hit 30 winners, converting three of her six break points, and moved on to face Sara Errani, who beat Zheng Jie 6-2, 6-1 later on Monday.
Sharapova, the fourth seed, was also in action Monday against 14th-seeded Sabine Lisicki.