Second seed Caroline Wozniacki, a semi-finalist in 2011, annihilated 19th-seeded Magdalena Rybarikova 6-3, 6-0 on Rod Laver Arena in her most impressive performance to date.
“She really mixes up the pace, I just tried to calm down, get my returns in and wait for the opportunities to attack,” she said after crushing the Slovak, who made the semi-finals at Wimbledon last year.
“I think you can tell my confidence is pretty good at the moment.”
The world number two from Denmark will face the unseeded Carla Suarez Navarro for a place in the semi-finals after advancing in just 63 minutes.
Svitolina into quarters
Elina Svitolina galloped into the last eight of the Australian Open with a late night 6-3, 6-0 demolition of Czech qualifier Denisa Allertova.
The Ukrainian sprinted through the match that did not start until 23:56 pm Sunday at Melbourne Park in 57 minutes.
She will face unseeded Belgian Elise Mertens for a place in the semi-finals.
Suarez Navarro advances
Spain’s Suarez Navarro blitzed into the quarter-finals with a stunning 4-6, 6-4, 8-6 win over Anett Kontaveit, who had earlier stunned French Open champion Jelena Ostapenko
The Estonian 32nd seed blew a set and 4-1 lead with two breaks to allow the 39th-ranked Spaniard back into the match. She also stumbled when serving for the match at 5-4 in the third, as the experienced Suarez Navarro reached her third Australian Open last eight after 2hr 15min.
“Was tough today. She started really well,” said the Spaniard who has also reached the quarter-finals twice at Roland Garros and also at the US Open, but never progressed further.
“I always have to fight to the end,” she added. “I just tried to play my game and stay really focused. I just run and run. That’s it.”
Mertens became first Belgian to reach quarters since Clijsters
Elise Mertens became the first Belgian to reach the quarter-finals of the Australian Open since Kim Clijsters in 2012 with a straight sets win over Petra Martic on Sunday.
The unseeded world number 37 edged the big-serving Croat 7-6 (7/4), 7-5 in almost two hours of baseline war on Margaret Court Arena.
In-form Mertens is making her Australian Open main draw debut and is on an nine-match win streak after making a successful title defence in the warm-up event in Hobart just over a week ago.
“I’ve had an amazingly good start to the year,” she said after having to grind out victory after leading 4-0 in the first set and being broken in the second when serving for the match for a first time.
She could next face another in-form player, fourth seed Elina Svitolina who won the Brisbane International warm-up.
The Ukrainian will first need to get through a late match against qualifier Denisa Allertova.
Mertens is in uncharted territory in her fifth appearance in the main draw of a Grand Slam.
She has only once before got past the opening round in a major, at Roland Garros last year when she reached the third round.
With inputs from AFP