Aryna Sabalenka and Coco Gauff restored order at the Australian Open by easing into the quarter-finals.

While Iga Swiatek's shock loss to Linda Noskova on Saturday means no top-10 seeds made the fourth round in the top half of the draw, Sabalenka and Gauff are on a semi-final collision course in the bottom half.

Neither has yet dropped a set and they lost only eight games between them in the fourth round, Sabalenka beating Amanda Anisimova 6-3 6-2 and Gauff racing to a 6-1 6-2 victory over Magdalena Frech.

It was a particularly impressive win and performance from defending champion Sabalenka, who had lost four of her previous five matches against Anisimova.

The 22-year-old American has been resurgent here having missed most of last season for mental health reasons but could not match the precision power of her opponent.

Anisimova reacted to the defeat by dropping her racket on the court and leaving it there as she walked off Margaret Court Arena.

"I'm super happy with the level, happy to get this win," said Sabalenka. "She's a tough opponent and I'm super happy to see her back on tour. I'm pretty sure she'll be back at the top soon.

"I really want to stay here as long as I can until the very last day and, hopefully, we can get this one one more time."

In the last eight, Sabalenka will face ninth seed Barbora Krejcikova, who ended the run of 16-year-old Mirra Andreeva with a 4-6 6-3 6-2 victory.

Gauff is treading new ground having made it through to the last eight at Melbourne Park for the first time.

"I'm super happy to be in this position and be here," said the 19-year-old. "I think I had three fourth rounds. It's cool to get over that hump. Hopefully I can keep going for more."

Next she will take on Ukraine's Marta Kostyuk, who made the last eight at a slam for the first time with a 6-2 6-1 victory over qualifier Maria Timofeeva.

Kostyuk had her breakthrough run here six years ago as a 15-year-old, reaching the third round, and she said: "Definitely a lot has changed. I really feel like it was in a different lifetime. A lot of things have happened in the past six years. I've changed probably six times already.

"I always say that I think change is always good. That means I'm not staying in one spot. Whether you feel like you're changing in the worst way or in the better way, I think it's good to keep all the change happening.

"It was a hell of a journey so far already. It's been a lot of years and I'm very happy I still feel fresh."