FIVE-TIME champion Serena Williams blamed a litany of mistakes after crashing out of the Australian Open to unseeded Russian Ekaterina Makarova.
The American was guilty of seven double faults and 37 unforced errors as Makarova claimed the most notable scalp of her career 6-2, 6-3.
“She played really well, she went for broke on a lot of shots,” said Williams, a 13-time grand slam winner. “I made 37 errors and that pretty much told the story of the match.”
Williams, who struggled with an ankle ailment before the tournament, admitted to being short of full fitness but insisted it was not the cause of her defeat to the world No56. She added: “I never blame any injury I have because I feel like she played really well and deserved the win."
Makarova, who will meet compatriot and fourth seed Maria Sharapova in the quarter-finals, said: “I won against Serena – that’s amazing. I'm surprised but I was feeling so good and so focused.”
Sharapova, chasing her first grand slam since her 2008 Melbourne triumph, came from behind to beat Germany’s Sabine Lisicki 3-6, 6-2, 6-3.
Second seed Petra Kvitova advanced to the last eight with a 6-2, 7-6 (7-2) victory over former Wimbledon champion Ana Ivanovic. Kvitova will next face Italy’s Sara Errani, who beat China’s Zheng Jie.