Wimbledon champion Garbine Muguruza has pulled out of the Sydney International with a thigh injury, five days before the start of the Australian Open.

The 24-year-old reached the quarter-finals with a 6-3 7-6 (8-6) win over Netherlands’ Kiki Bertens, 26.

But the top seed, who called for a medical timeout after the third game, withdrew hours after her victory.

“Since the start I felt a little bit my abductor,” the Spaniard said after claiming her first win of the season.

“I already felt it in Brisbane, so I thought I was going to be much better, but it came back.

“You always have to adapt. Sometimes you don’t need to have a pain. You just want to play a certain style of game or some tactic.”

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Despite only converting three of the 13 break-point opportunities in the second set, Muguruza sealed victory on her fourth match point in the tie-break.

It was a first win in four meetings with Bertens for Muguruza, who retired from last week’s Brisbane International with cramps.