Coco Gauff says she often forgets she is still a teenager after becoming the youngest woman to reach the Australian Open singles quarter-finals since 2008.

The 19-year-old American booked her spot in the last eight by sweeping past Poland’s Magdalena Frech 6-1 6-2.

“I’ve lived so many lives in the last four years that I just feel older than 19,” US Open champion Gauff said.

Defending champion Aryna Sabalenka continued her own serene progress by beating Amanda Anisimova 6-3 6-2.

Gauff and 25-year-old Sabalenka remain on course to meet in the Melbourne last four, which would give the Belarusian an opportunity to avenge her defeat in the US Open final.

After bursting on to the scene as a 15-year-old at Wimbledon in 2019, Gauff fulfilled her long-heralded potential by landing a first Grand Slam title in New York.

Now, in her final major tournament as a teenager, she is the second favourite at the Australian Open behind second seed Sabalenka.

“Sometimes I forget my age. I know I’m not going to be a teenager any more,” said Gauff, who is the youngest player to reach the Melbourne quarter-finals since Poland’s Agnieszka Radwanska.

“When I’m looking at the other girls on tour who are 16, 17, and now coming up, they just feel so young and I feel so old.

“I know I’m not that old, but I definitely do forget my age a lot.”

Gauff, who has not faced another seed, will play Ukraine’s Marta Kostyuk next, while Sabalenka faces either 16-year-old Russian Mirra Andreeva or Czech ninth seed Barbora Krejcikova.

Neither Gauff or Sabalenka have dropped a set at the first Grand Slam tournament of the 2024 season.

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Seeds falling but Gauff storms on

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 left 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 time.

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.

Gauff said she was “not too nervous” to play in front of the great Rod Laver – because she was already well on the way to victory when the 11-time major champion arrived on the court named after him.

“Luckily I was up a lot when I noticed he came in,” joked Gauff, who thanked the 85-year-old Australian for coming to her match.

Sabalenka moves on – with new superstition

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

She had lost her four past meetings with the American but needed just 70 minutes to seal victory at Melbourne Park.

The 25-year-old has developed a new superstition this week – signing her fitness coach’s head with a pen before each match.

“I did it before the first match,” she said. “Now it’s a routine.

“Every time he’s not super happy that I’m going to do that. He’s like, ‘OK, anything for the win’.”