Melbourne - Defending champion Novak Djokovic 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 as she beat America's Alison Riske 6-3, 1-6, 6-4.
"I just had to hang in there and try and give myself a chance," said Barty, who recovered from losing the second set, and stays on course to become the first Australian champion since 1978.
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 intense hype 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.
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.
Roger Federer plays Hungary's Marton Fucsovics in the late match as he seeks a record 15th appearance in the quarter-finals, two days after going the distance in a five-set thriller with John Millman.
The winner will play 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.
Results on day seven of the Australian Open Grand Slam at Melbourne Park on Sunday (x denotes seeding):
Milos Raonic (CAN x32) bt Marin Cilic (CRO) 6-4, 6-3, 7-5
Novak Djokovic (SRB x2) bt Diego Schwartzman (ARG x14) 6-3, 6-4, 6-4
Tennys Sandgren (USA) bt Fabio Fognini (ITA x12) 7-6 (7/5), 7-5, 6-7 (2/7), 6-4
Petra Kvitova (CZE x7) bt Maria Sakkari (GRE x22) 6-7 (4/7), 6-3, 6-2
Sofia Kenin (USA x14) bt Coco Gauff (USA) 6-7 (5/7), 6-3, 6-0
Ons Jabeur (TUN) bt Wang Qiang (CHN x27) 7-6 (7/4), 6-1
Ashleigh Barty (AUS x1) bt Alison Riske (USA x18) 6-3, 1-6, 6-4