Australian Open: Favourite Kerber relieved to avoid being latest star name to fall to Hsieh Su-wei

Hsieh plays a completely different game from most of her rivals, relying not on power but a mixture of spins and slices and ball placement to drive opponents to distraction.

Her scalps in Melbourne had already included Wimbledon champion Garbine Muguruza and Agnieszka Radwanska, and for a long time it looked like Kerber might join them.

But the 2016 champion has a deep well of confidence after her unbeaten start to the season and kept her composure to turn the match around and win 4-6 7-5 6-2.

Kerber said: “I was always like, ‘this is impossible’ how she hit the ball. All the time she had the better answer. It’s unbelievable. I’m really happy about how I was able to change the match and playing good tennis again in important moments, especially in the third set.”

In the last eight Kerber will face US Open finalist Madison Keys, who blasted her way past eighth seed Caroline Garcia, winning 6-3 6-2.

The 22-year-old has long been marked out as a potential grand slam winner but her first final experience in New York last summer was something of a horror show as she won just three games against friend Sloane Stephens.

World No 1 Simona Halep avoided the dramas of the third round to ease into the quarter-finals with a 6-3 6-2 victory over Naomi Osaka.

Halep suffered an ankle injury in the first round but is confident she can play through the pain.

“The ankle is still sore,” she said. “But I’m not thinking about that any more.”

In the quarter-finals, Halep will face sixth seed Karolina Pliskova, who finished off a 6-7 (5/7) 6-3 6-2 victory over fellow Czech Barbora Strycova.