Spain’s Garbine Muguruza said she barely avoided turning into a zombie before reaching the Australian Open last 16 on Saturday after playing her previous match in the middle of the night.

The two-time Grand Slam winner, seeded 18, defeated Timea Bacsinszky of Switzerland 7-6 (7/5), 6-2 to make the fourth round at Melbourne Park.

The 25-year-old’s previous match against Briton Johanna Konta set a record for the latest start in the tournament’s history after it began in the early hours of Friday morning.

The clash, which Konta condemned as dangerous and unhealthy, started at 12.30am and ended after a draining three sets at 3:12 am, the latest end to a women’s match at the Grand Slam.

She said it made preparation difficult for her match against Bacsinszky.

“I tried to fall asleep quickly and stay active a bit, not like a zombie,” she said. “But I felt good on the court.”

Muguruza, a quarter-finalist in Melbourne two years ago, will face either Czech seventh seed Karolina Pliskova or 27th seed Camila Giorgi of Italy in the next round.

The Spaniard is seeking to recapture the form that propelled her to the world number one ranking and delivered a French Open title in 2016 and Wimbledon a year later.