Two Top 10 seeds were eliminated from the Australian Open on Wednesday at the hands of perennial upset artist Hsieh Su-wei and former Grand Slam quarterfinalist Sorana Cirstea.
First up, the 35-year-old from Chinese Taipei was at her mercurial best for 83 minutes inside Rod Laver Arena, earning a 6-3, 6-2 upset over No.8 seed Bianca Andreescu behind six breaks of serve.
"I normally feel more excited to play with the better players because they have all the skills in the court," Hsieh said on-court after the match, "so you need to find a way to get through and play your game. It's always not easy."
The victory is Hsieh's eighth against a Top 10 player in the past four years, and marks the first time that the current doubles World No.1, now ranked No.71 in singles, has won consecutive matches solo since September of 2019.
Hsieh had previously lost her first 14 matches against the game's elite dating back to 2008 before scoring her first win in 2017.
The pair had previously played at the ASB Classic in 2019, where the Canadian beat Hsieh in straight sets en route to her first WTA singles final.
"She can do everything on court, so you always will get some surprise, and sometimes, you don't know if it's good for you or bad for you," Hsieh added in her post-match press conference, "so I try to manage some of the emotion there."
"I was thinking that I lost last time, so I need to be little bit stronger on the court. And last year, I was in the same court for the final of doubles and I was not doing very good, so I hope, I was thinking, 'I hope I play a little bit better today.'"
Utilizing her entire repertoire of shots across every inch of the court, Hsieh sprinted out the early leads in each set and hardly looked back to score the best victory of the tournament so far in terms of ranking.
Andreescu proved largely unable to encroach on deficits of 4-0 in the opener and 3-0 in the second set, despite briefly getting back on serve midway through the latter.
Eight of 10 points earned the 2019 US Open champion two consecutive games, but the combination of playing just her second match in 15 months against Hsieh's unorthodox playing style proved too much to overcome.
"I'm just disappointed that today that was my all because I know I gave my all today and to me I think that was the most disappointing part and that was like my initial evaluation of the match," Andreescu said.
"She played really well. I have to give credit to her. I definitely have to get back into the groove of things, and hopefully that will be sooner than later.
"I did play her before in Auckland and I played really, really well that match. She also played well. So today even in those tough moments [today], I thought I could break her a little bit, but she was on every single ball. I had a little bit of experience of what I was going to expect and I knew she was a really, really tough opponent. She likes to change it up, all that stuff.
"She's good at the net. She can come in. She can literally redirect any single ball you give her. Her serve doesn't have a lot of pace on it, but she can place it very well... The fact that she can change the rhythm. I know I can change rhythm too, but she's just on another level, at least today."
Cirstea eliminates Kvitova on MCA
While Hsieh has made upsetting the game's best on the biggest stages something of a specialty, Sorana Cirstea hadn't scored a Top 10 win at a Grand Slam in nine years. Until today.
The Romanian overcame No.9 seed Petra Kvitova in a shade over two hours, 6-4, 1-6, 6-1, on Margaret Court Arena, to reach the third round of the Australian Open for the first time since 2017.
Cirstea had last beaten a Top 10 player at a Grand Slam when she knocked off then-World No.5 Samantha Stosur in the first round of the 2012 Australian Open, and picked up a 15th career win over a player in that ranking range overall.
The Romanian rallied from 3-1 down in the opener to win it, and managed to bounce back for an emphatic decider after going 0-for-6 on break points in the middle set.
"In the second set, she stepped up a bit and I backed off. I think today was a matter of who took control of the points," Cirstea said.
"I think in the second set I played too defensive, but once that was over, I tried to get back closer to the lines, to try to dictate the points, and it worked."
More from the Australian Open: Serena surges into third round
Kvitova came into the match with a 5-2 head-to-head edge against the former World No.35, and dropped just four games in their last meeting at a Grand Slam - a first-round win at Wimbledon five years ago.
"It was quite a roller coaster, for sure. I unfortunately couldn't take the chances to win the first set. I think that was really the key of the match," Kvitova said in defeat.
"I played great second set. I think all the games which we played over those two hours were pretty close, was a lot of deuces. She just took it. She really had a great day today. She played a good game.
"I should have take the first set when I was leading a break. I was really fighting, losing four or five games in the row. This can't happen to me unfortunately."
Bidding to match her best result at the Australian Open, a fourth round showing from four years ago, Cirstea will next face No.19 seed Marketa Vondrousova.
The 2019 French Open finalist and World No.20 rallied from 5-3 down in the second set to beat the Canadian qualifier, 6-1, 7-5, to end the latter's first Grand Slam appearance in eight years.
Sabalenka, Muguruza move safely through
Around the grounds, No.7 seed Aryna Sabalenka and No.14 seed Garbiñe Muguruza came through contrasting second round wins over Daria Kasatkina and Liudmila Samsonova, respectively.
The Belarusian was twice a break down against the former Top 10 player in the opening set en route to a 7-6(5), 6-3 win on Margaret Court Arena, and eked out a first set tiebreak despite seeing a 5-2 lead slip away.
Conversely, Muguruza was dominant in a 6-3, 6-1 showing against the World No.130 in 64 minutes.
After neither player faced break point in the first six games, the former World No.1 won eight straight - and sealed victory after being denied two match points for the bagel.
"I am very happy the way I played. I had an opponent that I didn't know much. We haven't met before. It's not often that you play someone you don't know anything about," Muguruza said.
"I was happy that I got the first set. That was a tight set. Then in the second set I kind of knew more about her game and took the lead early, then could close it in two sets. With this heat and everything, I was happy it didn't got complicated and long."
The 2020 finalist moves on to face Kazakhstan's Zarina Diyas, a 6-4, 3-6, 6-3 winner over American Bernarda Pera.