Halep put away Kazakhstan's Yulia Putintseva 6-1, 6-4 to reach the last 16, where she will play Belgium's Elise Mertens, who won in three sets against CiCi Bellis -- ending the American's Grand Slam return from long-term injury
World number one Rafael Nadal and Wimbledon champion Simona Halep dodged an exodus of seeded players as the shocks kept rolling at the Australian Open on Saturday.
After Serena Williams and title-holder Naomi Osaka fell by the wayside on Friday, second seed Karolina Pliskova crashed out on a day of carnage in the women's draw.
Switzerland's Belinda Bencic, the sixth seed, won only one game against Estonia's Anett Kontaveit, the world number 31, as she bombed 6-0, 6-1.
And a resurgent Garbine Muguruza, a two-time Major-winner, thrashed fifth seed Elina Svitolina 6-1, 6-2 as six of the top 10 women's seeds exited in round three. Tenth seed Madison Keys lost to Maria Sakkari on Friday.
"I was very concentrated and focused on what I wanted to do, it all went fast my way," said Muguruza, who raced through the first set in just 23 minutes.
Croatian 19th seed Donna Vekic also crumbled to lower-ranked opposition when she lost 7-5, 6-3 to Poland's Iga Swiatek, who is returning from a stress fracture in her foot.
While the women's seeds fell, Nadal had few problems against fellow Spaniard Pablo Carreno Busta -- despite staying up to watch Roger Federer's thrilling late-night win over John Millman, which went to a fifth-set tie-breaker.
"I watched it until one o'clock -- it was impossible to sleep watching this match," Nadal said.
But he showed no signs of tiredness, racing through 6-1, 6-2, 6-4 in just 1hr 38mins in what he called his "best match of the tournament so far, without a doubt".
"I'm improving every day, so super-happy. I did well on my serve and hit good forehands down the line, which is a key shot for me," he said.
Nadal, 33, who can equal Federer's record 20 Grand Slam titles with victory in Melbourne, will now meet either Karen Khachanov or Nick Kyrgios -- the outspoken Australian with whom he has a running feud.
Kyrgios, who labelled Nadal "super salty" last year, and mimicked his serving routine during his second-round win, has his biggest test yet against the Russian 16th seed, who won their only meeting in Cincinnati last year.
Germany's Alexander Zverev dismissed Fernando Verdasco 6-2, 6-2, 6-4 to set up a last-16 clash with Russia's Andrey Rublev, who remained unbeaten this year with his win over David Goffin.
Halep put away Kazakhstan's Yulia Putintseva 6-1, 6-4 to reach the last 16, where she will play Belgium's Elise Mertens, who won in three sets against CiCi Bellis -- ending the American's Grand Slam return from long-term injury.
Halep, the reigning Wimbledon champion, shrugged off the departure of some of the tournament favourites, saying defeats can happen to anyone.
"It's just a tournament, and I'm sure that for you guys (media) it's a little bit of shock when the top-10 players are losing, but it's life and we cannot be 100 percent every day," said the Romanian.
Angelique Kerber, the 2016 champion, beat Camila Giorgi 6-2, 6-7 (4/7), 6-3 to set up a meeting with Russia's 30th seed Anastasia Pavlyuchenkova, who knocked out Pliskova 7-6 (7/4), 7-6 (7/3).
.@NickKyrgios GETS THE WIN— Live Tennis (@livetennis) January 25, 2020
6-2, 7-6(5), 6-7(6), 6-7(7), 7-6(10-8) over Karen Khachanov in four hours & 30 minutes.
IT WILL BE KYRGIOS VS NADAL ON MONDAY NOT SORRY FOR YELLING #AusOpen pic.twitter.com/AfLT9AHamS
"I was about 40 percent today of my game," said Pliskova, who was at a loss to explain her lack of form. "I don't know. I was just down."
In other results, Austrian fifth seed Dominic Thiem came through 6-2, 6-4, 6-7 (5/7), 6-4 against Taylor Fritz, and Russia's Rublev beat Goffin 2-6, 7-6 (7/3), 6-4, 7-6 (7/4).
Stanislas Wawrinka, the 2014 champion, progressed to the last 16 when John Isner retired in the second set, and Gael Monfils beat Ernests Gulbis 7-6 (7/2), 6-4, 6-3.