Iga Swiatek admitted the pressure of the world number one tag got to her after crashing out of the Australian Open in the fourth round to Wimbledon champion Elena Rybakina.
The Russian-turned-Kazakh has spoken of her frustration at not being scheduled on the main courts since her success at the All England Club and, on Rod Laver Arena, she produced a big-stage performance to win 6-4 6-4.
Rybakina, who would be in the top 10 had Wimbledon offered ranking points, dropped only six points on her first serve during the match and recovered from 3-0 down against a frustrated Swiatek.
The result, coupled with defeats for Ons Jabeur, Rafael Nadal and Casper Ruud, means for the first time in the open era, the top two seeds in both the men's and women's draws have lost before the quarter-finals.
While it is a big shock, Swiatek is not as dominant on hard courts as she is on clay and, although she has talked here of not expecting herself to win every match, it is clear the Pole finds it difficult to temper those expectations.
"For sure the past two weeks have been pretty hard for me," said Swiatek, who won the French and US Opens last year.
"So I felt today that I don't have that much to take from myself to fight even more. I felt like I took a step back in terms of how I approach these tournaments, and I maybe wanted it a little bit too hard. So I'm going to try to chill out a little bit more.
"I felt the pressure, and I felt that I don't want to lose instead of I want to win. So that's, I think, a base of what I should focus on in the next couple of weeks."
This was a meeting between the only two current active female grand slam champions, and Rybakina made the perfect start by breaking Swiatek's serve from 40-0.
Swiatek, who had received a warning before the start for taking too long to be ready to play, pulled back to 2-2 but the flatter hitting of Rybakina was paying dividends on a warm, sunny day in Melbourne and she forged ahead again to lead 4-3 and took the opening set.
Swiatek looked set to mount a comeback when she broke the Rybakina serve in the second game of the second but back came the 22nd seed.
Swiatek had never quite looked comfortable and she was unable to withstand the pressure in the ninth game, with Rybakina breaking and then serving out the match to love to reach the quarter-finals at Melbourne Park for the first time.
In the last eight, Rybakina will play a resurgent Jelena Ostapenko, who powered her way to a 7-5 6-3 victory over seventh seed Coco Gauff.
A surprise winner of the French Open in 2017 aged 20, Ostapenko has struggled in recent years but last season saw her climb back up the rankings and she is through to this stage of a grand slam for the first time since reaching the Wimbledon semi-finals in 2018.
Ostapenko simply had too much power for Gauff, who is one of the best defenders on tour but was unable to land her big first serve as often as she needed and paid the price.
It was a first defeat of the season for the 18-year-old following her title in Auckland and Gauff, who is still playing in doubles, shed tears of disappointment in her press conference.
"I think it's because I worked really hard, and I felt really good coming into the tournament, and I still feel good," she said. "I feel like I've improved a lot. But, when you play a player like her and she plays really well, it's like there's nothing you can do."
Former world number one Victoria Azarenka reached her first Austalian Open quarter-final for seven years as she fended off China's Zhu Lin 4-6 6-1 6-4 in the early hours of Monday.
Azarenka, twice a winner of the title in Melbourne, started slowly and lost the opening set but stormed through the second to take the fourth round match into a decider.
Neither player could hold serve in the third set but Azarenka's greater experience finally pulled her through.
The Belarusian wobbled when serving for the match at 5-4 but hit back from 15-40 to complete the victory at 2.15am local time with an angled crosscourt backhand winner.
Azarenka, 33, will face third-seeded American Jessica Pegula for a place in the semi-finals.
"I feel so relieved, it was complete pressure, lots of momentum shifts, there was everything in this match," 24th seed Azarenka said on a sparsely-populated Rod Laver Arena.
"Happy I could handle everything and take my chances and went for it. I've had a couple of close matches this year that didn't go my way so I'm really proud of myself."
Looking ahead to her quarter-final she said it would be a more familiar opponent, having known liitle about Zhu Lin.
"I've practised a lot with Jess and I'm going to enjoy that one. If I do lose I would rather lose to Jess, but I'm going to give her hell!"
