Djokovic, hunting his eighth Melbourne title, was remorseless against Argentina's Diego Schwartzman, crushing the 14th seed 6-3, 6-4, 6-4 to book an 11th appearance in the last eight
Novak Djokovic and Roger Federer swept into the Australian Open quarter-finals but 15-year-old Coco Gauff exited in tears on Sunday after her quest to become the Open era's youngest Grand Slam winner came screeching to a halt.
As Melbourne marked Australia Day with formation jets and a 21-gun salute, world number one Ashleigh Barty had home fans celebrating before crowd favourite Federer dismantled Marton Fucsovics in the night match.
Djokovic, hunting his eighth Melbourne title, was remorseless against Argentina's Diego Schwartzman, crushing the 14th seed 6-3, 6-4, 6-4 to book an 11th appearance in the last eight.
The Serb's reward is a match-up with big-serving Canadian Milos Raonic, who is back in form after a run of injuries and dismissed 2018 finalist Marin Cilic 6-4, 6-3, 7-5.
"I've got to be ready for missiles coming from his side of the net," said Djokovic, the 16-time Grand Slam winner.
Gauff's giant-killing Australian debut generated hype dubbed 'Cocomania' as she attempted to become the youngest Major winner in the post-1968 Open Era, breaking the record set by a 16-year-old Martina Hingis in 1997.
Gauff beat seven-time Grand Slam champion Venus Williams in round one and title-holder Naomi Osaka in the third, but she came unstuck against a determined Sofia Kenin.
Coco Gauff's Grand Slam run at age 15 ended with a loss in the Australian Open's fourth round to Sofia Kenin https://t.co/itjvU2Jejf— Sports Illustrated (@SInow) January 26, 2020
Gauff raised hopes by edging the first set but then her fellow American took control and it was one-sided at the finish as Kenin won 6-7 (5/7), 6-3, 6-0.
"The thing I'm most proud of myself is how I handled it on the court," said Gauff, who shed tears after her defeat. "Even though today I lost a set 6-0, I was still believing I could win it."
Kenin, already on the best Grand Slam run of her career, next faces Tunisia's Ons Jabeur, who beat China's Wang Qiang to become the first Arab woman to reach a Major quarter-final.
Wang stunned Serena Williams in the third round but the 27th seed ran out of steam against Jabeur, who fought back from a break down in the first set to win 7-6 (7/4), 6-1.
Jabeur, the highest-ranked Arab woman in history -- she reached a career-high 51 last year -- is the first Tunisian woman to win a main-draw match at the Australian Open.
"I'm really shaking right now, it's unbelievable, I can't describe how I feel," said the 25-year-old.
Australia's Barty had some nervy moments against American Alison Riske, dropping the second set and briefly losing her way before recovering to win 6-3, 1-6, 6-4.
She now has an improving chance of becoming the first home-grown winner since Chris O'Neil in 1978 after six of the top 10 seeds exited in the previous round.
"I just had to hang in there and try and give myself a chance," said Barty, who next plays Petra Kvitova, after the two-time Wimbledon champion beat Maria Sakkari 6-7 (4/7), 6-3, 6-2.
Later, Federer sent ripples of consternation around Rod Laver Arena when he dropped the first set against Hungary's Fucsovics, the world number 67.
But the 38-year-old Swiss, pushed to a fifth-set tie-breaker by Australia's John Millman on Friday, came alive in the second set as he rattled through the match 4-6, 6-1, 6-2, 6-2.
"It just took me some time, I tried to mix it up a bit and just had to figure it out. From the beginning of the second set it got a little bit easier," Federer said.
The 20-time Grand Slam champion's quarter-final is against unseeded American Tennys Sandgren, who upset Italian 12th seed Fabio Fognini in four tough sets, 7-6 (7/5), 7-5, 6-7 (2/7), 6-4.