Nadal will now face Canada's 14th seed Denis Shapovalov after he stunned third seed and Olympic champion Alexander Zverev -- who said "everything" went wrong.

Nadal, who is chasing a men's record 21st Grand Slam title, was pushed all the way by Adrian Mannarino in an 81-minute first set before breaking the Frenchman's resolve in a 7-6 (16/14), 6-2, 6-2 victory.

"First set was very emotional," said the 35-year-old Nadal, the 2009 Australian Open champion, who pumped his fists after emerging victorious from a marathon first-set tiebreak on a steamy day in Melbourne. 

"That crazy first set was so important."

The Spaniard, who dropped a set for the first time in the tournament before powering past Russia's Karen Khachanov in the previous round, will now face Shapovalov in the last eight.

The 22-year-old Shapovalov -- who caught COVID before the Slam and was not even sure he would play in Melbourne -- left Zverev still searching for a first major title after convincingly beating him 6-3, 7-6 (7-5), 6-3.

The German smashed his racquet and afterwards failed to find any positives.

"Today, in my opinion, was just awful from my side," he said.

Asked what went wrong by reporters, he replied: "Everything."

Flashy French 17th seed Gael Monfils warned that "I'm not quite finished yet" after he surged past Miomir Kecmanovic of Serbia to set up an encounter with Italian seventh seed Matteo Berrettini.

The 35-year-old Monfils is yet to drop a set in Melbourne.

Big-serving Berrettini sent down 28 aces to blow away Spain's Pablo Carreno Busta in three sets.

"He's feeling good, I'm feeling good," he said of his clash with Monfils.

"It's going to be a fight."

 

Barty powers on

In the women's draw, home hope and world number one Barty thrilled the crowd by defeating 60th-ranked Anisimova 6-4, 6-3. The Australian faces another American, Jessica Pegula, in the last eight.

The 20-year-old Anisimova beat Olympic champion Belinda Bencic and was fresh from knocking out defending champion Naomi Osaka.

But she came up against a Barty who looks in irresistible form as she chases her first Australian Open crown.

Reminded that last year's Australian Open went behind closed doors mid-tournament because of COVID, Barty told an adoring Rod Laver Arena crowd that playing in front of them was "a lot more fun".

"Last two years have been extraordinarily tough for many people around the world," said the down-to-earth 25-year-old, the reigning Wimbledon champion and a former Roland Garros winner.

The 21st-seeded Pegula, who revealed earlier this week she has been relaxing by spending every night at the casino, was a surprise winner over fifth seed Maria Sakkari of Greece.

Also into the last eight is French Open champion Barbora Krejcikova, who looks in ominous touch.

She blew away former two-time Melbourne champion Victoria Azarenka, who had a neck problem, to set up a meeting with unseeded American Madison Keys.

Fourth seed Krejcikova of the Czech Republic powered through 6-2, 6-2 against the Belarusian, who won the title in 2012 and 2013.

"It was really amazing today because she is a champion here and she likes this court, she's very experienced on this court," said Krejcikova of Azarenka.

Keys raced past Spain's Paula Badosa, seeded eight, 6-3, 6-1.

Keys, who beat 2020 champion Sofia Kenin in the first round, said she had brought a fresh perspective into 2022 after struggling with the COVID-enforced bubble life on tour last year.

"I don't really thrive when my entire life becomes about tennis," she said.