serena williams*(Via TheGrio) – Novak Djokovic looked vulnerable for the first time at this Australian Open when Lleyton Hewitt won six straight games to take a set in the last match of a day that had already featured a stunning, upset loss for Serena Williams.

Top-ranked and defending champion Djokovic held his composure and survived to win in four sets late Monday night, ensuring all of the top five men reached the quarterfinals.

Numbers told the surprising story for Williams in her fourth-round loss: seven double-faults, including four in one game; 37 unforced errors, and a first-serve percentage of just over 50 percent had her convinced “maybe I should have started serving lefty.”

Some other numbers indicated why her 6-2, 6-3 loss to Russia’s Ekaterina Makarova on what she admitted was a still-sore left ankle was more of a shock.

She has played 43 singles matches at Melbourne Park since she won the first of her five Australian Open titles in 2003, and Monday’s loss was just her third. She’s 54-7 since playing here for the first time in 1998, and she hasn’t gone out this early here since 2006.

“I’m not physically 100 percent, so I can’t be so angry at myself, even though I’m very unhappy,” Williams said. “I know that I can play a hundred times better than I did this whole tournament.”

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