Seeded players have been falling quickly in the women’s singles, with only four of the top 16 left after the first week and just seven remaining in total.

Belarusian Victoria Azarenka, seeded 18th, is the only Grand Slam champion in the top half of the draw after world number one Iga Swiatek’s shock third-round defeat on Saturday.

Gauff, 19, ensured she did not face the same fate with a clinical and composed performance against Frech, who was competing in the last 16 of a major for the first.

After beginning the year by winning a WTA title in Auckland, Gauff continued a perfect start to the season by sweeping past the 69th-ranked Pole for her ninth straight victory.

The American broke serve in the first game on and allowed Frech to win just 10 more points in a 26-minute set.

Two more breaks of serve followed in the second set as Gauff breezed through without facing a break point.

In her first Melbourne quarter-final, she will face Kostyuk after the world number 37 easily beat Russian qualifier Maria Timofeeva 6-2 6-1.

Looking for a second major title after fulfilling her long-heralded potential in New York, Gauff is the second favourite behind 25-year-old Sabalenka.

Sabalenka has been in similarly devastating form – dropping just six games in her opening three matches – and producing another dominant display against 22-year-old Anisimova.

“I’m super happy with the level and happy to get this win,” said Sabalenka.