Ekaterina Makarova after defeating Serena Williams, in Melbourne, on Monday. (Getty Images)
Melbourne: Five-times champion Serena Williams lost for the first time in four years at the Australian Open on Monday but Novak Djokovic moved into the quarter finals despite picking up a few battle scars against Lleyton Hewitt.
The American, a dominant force at the years first Grand Slam for the past decade, showed signs of wear and tear as she crashed 6-2, 6-3 to world No. 56 Ekaterina Makarova in the fourth round, ending a 17-match winning streak here.
World No. 2 Petra Kvitova booked her place in the last eight with a 6-2, 7-6 win over Serbian Ana Ivanovic but the main talking point of the Wimbledon champions win was an air shot when she lined up an easy smash.
Maria Sharapova was also staring into the abyss against Sabine Lisicky before surviving for a 3-6, 6-2, 6-3 win.
On a day of surprises, Kei Nishikori beat French sixth seed Jo-Wilfried Tsonga in five sets to become the first Japanese to reach the quarter-finals of the Australian Open for 80 years. He will now face Andy Murray after the Briton needed less than an hour to move past Mikhail Kukushkin.
The world No. 4 was leading 6-1, 6-1, 1-0 when the Kazakh retired with a hip injury.
Williams, who won the title in 2009 and 2010 but missed out last year because of a career-threatening foot injury, was a pale imitation of her normal belligerent self as she crumbled to defeat in sweltering conditions at Rod Laver Arena.
She plans to take a course in kinesiology, the study of human movement, when she returns to the U.S. and the 30-year-old looked in dire need of some instruction after a stiff, lacklustre display.
The 13-times Grand Slam champion, who was the last American standing at Melbourne Park, had carried a sprained ankle into the tournament and was clearly not herself against a player showing scant regard for reputations.
Obviously Im not 100 percent, and I havent been. But its no excuse or anything, a dejected Williams told reporters. I know that I can play 100 times better than I did this whole tournament. She went for broke on a lot of her shots. I made 37 errors. That tells the story of the match.
Russian Makarova conceded she had been scared stiff the first time she played Williams at the 2008 Olympics but it was a different story on Monday.
I played her in Beijing and I was really afraid of her because shes a great player and its really tough to play against her, she beamed. But this time, I dont know, I felt so comfortable. I really thought that I could beat her.
Serbian Djokovic had used the blue hardcourts at Melbourne Park as a springboard for his spectacular 2011 when he won three Grand Slam titles and vaulted to the worlds top ranking.
He had not dropped a set in three quick-fire wins at the years first Grand Slam but 30-year-old Hewitt was never going to do down without a fight and battled for almost three hours before Djokovic completed a 6-1, 6-3, 4-6, 6-3 win.
Im not looking for excuses, but Im saying its obviously the first match that Ive been tested. It was against the player that I expected to be tested, said top seed Djokovic.
Nishikori, trumpeted as one of the new generation of players who can challenge the establishment, stunned Tsonga, winning 2-6, 6-2, 6-1, 3-6, 6-3 to emulate countrymen Ryosuki Nunoi and Jiro Satoh, who both made the last eight in 1932.