Coco Gauff said on Sunday she felt "invincible" after the recent United Cup and is not fazed about dropping her first set in nine matches this season in reaching the Australian Open quarterfinals.
The American world No 3 beat Switzerland's Belinda Bencic 5-7, 6-2, 6-1 on a red-hot Rod Laver Arena to set up a meeting with 11th seed Paula Badosa of Spain.
"Two out of three sets at this stage of my career is not that physically hard for me," said the 20-year-old Gauff, who is chasing a first Melbourne title.
"The off-season I just put in so much work physically so I'm not worried at all about recovering emotionally or mentally," added Gauff, who won all five of her singles in Perth and Sydney to lead the US to a United Cup team triumph.
Order of Play | Watch Live on DStv
"The United Cup was a little bit more exhausting because of the fact that I finished at 1:00 am one night, then had to fly across the country and play.
"That was more of the mental, emotional test.
"Honestly, I feel like after playing that whole United Cup, I felt pretty invincible."
Gauff added that 34 degrees Celsius (93 Fahrenheit) temperatures during her match on Sunday did not bother her.
"I guess weather-wise, I felt pretty confident in my physicality," she said after her ninth victory of the season and 13th straight going back to last year's WTA Tour Finals.
"Being from Florida, like it was hot, but Florida in September, August, is really disgusting," she added.
The fourth-round encounter went with serve in the early skirmishes but the big-hitting Bencic's ability to mix up her shots unsettled the American.
Gauff had not dropped a set in eight matches this season, but was put under the pump by Bencic who converted a second break point in the ninth game.
"I thought in the first set that she played great tennis and it was tough for me to be on the offensive," said Gauff.
"I just played more aggressively in the second set and then also the third set. Overall, I'm happy with how I played."
Gauff turned it around in the second set to take it to a decider.
Tokyo Olympic gold medallist Bencic came in with a 2-1 win-loss record over Gauff but their last meeting was in 2023.
A few weeks later Bencic took maternity leave to give birth to daughter Bella and she only returned to tennis at the end of 2024.
A hard-fought hold after three deuces set the American on her way at the start of the third set as Bencic started to feel the heat.
Gauff wore her down and broke for 3-1 before closing out Bencic in 2hr 26min.
Badosa, who beat Serbia's Olga Danilovic 6-1, 7-6 (7/2), is into a quarterfinal at Melbourne Park for the first time.
SABALENKA BLOWS AWAY ANDREEVA
Aryna Sabalenka stayed on course for a historic third consecutive Australian Open crown, ruthlessly blowing away teenager Mirra Andreeva to reach the quarterfinals.
Sabalenka was in irresistible form on Rod Laver Arena, powering to a 6-1, 6-2 victory in just 62 minutes against the Russian 17-year-old, the Belarusian's 18th consecutive win at Melbourne Park.
"I'm super happy to get through this difficult match in straight sets," said Sabalenka, who will face either Croatian 18th seed Donna Vekic or 27th seed Anastasia Pavlyuchenkova from Russia next.
"She's so young but always playing great tennis, it's always tough battles against her."
Despite registering three straight-sets wins, Sabalenka had not been at her imperious best during the first week.
She dropped serve three times in the second round and five times before battling past Clara Tauson 7-6 (7/5), 6-4 to reach the last 16.
She had no such problems in much warmer conditions against Andreeva, ripping through her first two service games without conceding a point and breaking for a 4-1 lead.
"Previous days were such tough conditions, the ball was so heavy," said Sabalenka.
"The ball was flying like a rocket. I hope conditions are going to be the same till the end of the tournament."
Andreeva struggled to live with Sabalenka's power and was being pushed further back as the champion pulled off a deft drop shot winner to lead 5-1.
A delicious backhand pass clinched the set in just 24 minutes.
Sabalenka did not let up at the start of the second set, an early break giving her a 3-1 cushion.
Andreeva showed a fleeting glimpse of her talent when saving two break points in the next.
She then created three of her own, but all were saved and the Sabalenka juggernaut could not be stopped as she cruised to the finish line.
Sabalenka can complete a hat-trick of Australian Open consecutive wins.
It is a rare feat last achieved 26 years ago by Martina Hingis and only matched by four other women in history, all legends of the sport.
Margaret Court, Evonne Goolagong, Steffi Graf and Monica Seles are the others to complete the treble.
BADOSA GUNNING FOR 'REVENGE'
Paula Badosa declared she "loves" Coco Gauff – but that will not prevent her looking for "revenge" when they face off in the quarterfinals.
Badosa, the 11th seed from Spain, swept aside Serbia's Olga Danilovic 6-1, 7-6 (7/2) to reach a last-eight clash with the American world No 3.
"I love Coco. I respect her a lot," Badosa told reporters of the 20-year-old.
"She's a great competitor. We always have tough matches."
The pair have a 3-3 head-to-head record but Gauff won both their meetings in 2024, with each going to three sets.
The last time was in the semifinals of the WTA China Open in Beijing, where Gauff won 4-6, 6-4, 6-2 on her way to lifting the title.
"Last one was really tough for me because I was winning in that moment, then the momentum changed," said Badosa, 27, who is prepared to go the distance again.
"I hope I can have my revenge here. It's a special match, quarterfinals, centre court, against her," added Badosa, who is into a quarterfinal at Melbourne Park for the first time.
"I always enjoyed playing against her. I respect her so much. I will get ready for that battle again.
"She didn't lose a match this year, if I'm not wrong. She's full of confidence. But I'm playing well, too. I'm ready to face her."
The last time a Spanish woman reached the last eight at the Australian Open was in 2020 when Garbine Muguruza achieved the feat.
Badosa can reach a maiden Grand Slam semifinal if she beats Gauff on Tuesday, having also reached the last eight at Roland Garros in 2021 and the US Open last year.
"I haven't experienced a lot of (Slam) quarterfinals. I need to experience more of these moments to know how to deal and to face them.
"My dream is always to be in the final rounds of a Slam. It would mean a lot."