France's Caroline Garcia produced the biggest upset of the US Open on Wednesday, sending top seed Karolina Pliskova tumbling out of the tournament.
Garcia, the world number 50, scored one of the biggest wins of her career with a 6-1, 7-6 (7/2) second-round victory at Louis Armstrong Stadium.
The 26-year-old's 1hr 33min victory sends her into a third round meeting on Friday with American 28th seed Jennifer Brady.
If she can reproduce Wednesday's polished performance, Garcia will fancy her chances of extending her run at Flushing Meadows.
Garcia -- whose talent propelled her to fourth in the world rankings in September 2018 before a protracted slump sent her sliding down the standings in 2019 -- attacked Pliskova from the outset.
Garcia raced into a 5-0 lead after scoring two early service breaks before taking the first set.
Although Pliskova improved in the second, she was unable to find the crucial service break when it mattered, and was unable to convert a set point in the second to level the match.
In the tie break, Garcia raced into a 6-2 lead and then completed victory when Pliskova hit a return into the net.
"I knew I was capable of causing problems for her," Garcia said. "I took my chances. When she came in the second set, there wasn't much more I could do. So I had to keep calm and just play it point-by-point."
- 'I'm not a robot' -
It was a disappointing exit for Pliskova, who had been elevated to No.1 seed after a slew of high-ranking player withdrawals due to the coronavirus.
"I thought she played great tennis in the first set. She was just playing super aggressive, going for her shots," Pliskova said. "I maybe didn't play my best.
"But that's how it is sometimes. I'm not a robot, so I don't have to play every day amazing."
While Pliskova fell by the wayside, there were no such problems for fourth seed Naomi Osaka of Japan, the 2018 champion.
The 22-year-old dominated hard-hitting Italian opponent Camila Giorgi in an emphatic 6-1, 6-2 victory.
"Even if I play a power player, for me, my goal is to be the dictator," Osaka said.
"I was able to do that quite well," added Osaka, who will now play Marta Kostyuk of Ukraine in the last 32 on Friday.
Elsewhere on Wednesday, Petra Kvitova advanced to the third round with a straight sets defeat of Kateryna Kozlova of Ukraine, winning 7-6 (7/3), 6-2.
Czech sixth seed Kvitova, chasing a third Grand Slam crown after wins at Wimbledon in 2011 and 2014, needed 1hr 40min to claim her place in the last 32.
The 30-year-old will face Jessica Pegula of the United States in the third round.
Croatia's Petra Martic, seeded eighth, defeated lowly ranked Kateryna Bondarenko of Ukraine 6-3, 6-4.
Martic, who reached the fourth round at Flushing Meadows last year in what remains her best US Open appearance, will face Russia's Varvara Gracheva in the third round.
Gracheva, ranked 102nd in the world, upset France's 30th-seeded Kristina Mladenovic 1-6, 7-6 (7/2), 6-0.
Mladenovic suffered a meltdown for the ages as she slid to defeat, collapsing from a 6-1, 5-1 lead and blowing four match points along the way.
"It is definitely the most painful match and loss I have had in my career because it's a Grand Slam," a disconsolate Mladenovic said afterwards.
"I was playing really good tennis there and I just couldn't close it out, couldn't convert my match points. I didn't take my chances. I just collapsed. I had nothing left in the tank."
Another seed to tumble was the Czech Republic's Marketa Vondrousova. The out-of-sorts 12th seed was beaten 6-1, 6-2 in little more than an hour by Belarus' Aliaksandra Sasnovich.
Germany's Angelique Kerber, the 2016 US Open champion, booked her place in the third round with a straight sets win over compatriot Anna-Lena Friedsam.
The 17th seed progressed with a 6-3, 7-6 (8/6) victory in 1hr 40min, and will now face Ann Li, who knocked out 13th seed Alison Riske 6-0, 6-3.