Melbourne, Jan 23 (IANS): Spanish third seed Garbine Muguruza on Saturday joined the ever-growing list of top ranked women to crash out of the Australian Open's first week.

Muguruza was sensationally upset by Czech tennis veteran and world No.48 Barbora Strycova, who easily outplayed a listless Muguruza 6-3, 6-2 in just over an hour, reports Xinhua.

The result means the Spaniard joins second seed Simona Halep, sixth seed Petra Kvitva, eighth seed Venus Williams and ninth seed Karolina Pliskova as the top-10 casualties at the open, and she admitted that she wasn't on top of her game on Saturday.

"I felt like I had not so much energy, that's for sure," Muguruza said in her press conference.

"I felt I was not moving very well. I guess also Barbora was making me move -- she was being smart."

Strycova, who has previously made the fourth round of a Grand Slam just once in her 13-year career on tour, said she had mentally prepared ahead of facing the third seed.

"I was serving very well and the plan was to play my game, play deep," Strycova said post-match.

"It's not easy against Garbine because she plays fast. But I think she didn't have the best day and I did."

Strycova moves on to the last 16 to play two-time Australian Open champion Victoria Azarenka, who -- incidentally -- has knocked the Czech woman out of the tournament twice - in both 2014 and 2015.