Petra Kvitova could have replaced Serena Williams as the world No 1 by winning the US Open but the Wimbledon champion was swept out of the tournament in the third round here by a qualifier ranked No 145 in the world.
Aleksandra Krunic, a 21-year-old Serb playing in only her second Grand Slam tournament, won 6-4, 6-4 as Kvitova became the fifth of the top eight seeds to go out, joining Simona Halep, Agnieszka Radwanska, Angelique Kerber and Ana Ivanovic on the list of casualties.
Krunic defended superbly, chased down balls which most would not have reached and played some superb drop shots, but the result was mostly down to Kvitova’s mistakes. The Czech, 24, made six double faults, some of them at crucial moments, and 34 unforced errors.
Although she has never gone beyond the fourth round here, Kvitova arrived in good form, having won the title at New Haven last weekend. However, she suffers from asthma and can look distressed in the heat.
At 25C it was not especially hot, but there were times when Kvitova looked lethargic, especially in comparison with the lively Krunic. The Serb, who is quick and very light on her feet, kept forcing Kvitova to hit the extra ball and pulled her around the court with her clever drop shots and injections of pace.
Krunic, whose only previous Grand Slam appearance was when she fell in the first round here last year, had won three matches in qualifying to reach the main draw and recorded her first victory over a top 30 player when she beat Madison Keys in the second round.
The Serb had treatment on her right ankle after a fall midway through the first set but recovered to make a decisive break of serve in the ninth game. From 30-30 she hit a backhand winner down the line before Kvitova double-faulted. The set was sealed when Kvitova made two successive backhand errors in the following game.
When Kvitova won the first two games of the second set it seemed that a crisis might have been averted, but Krunic won the next four games. At 2-4 down Kvitova saved two break points, but at 4-4 she was broken again when she hit a wild backhand beyond the baseline. Krunic, who enjoyed great support from the crowd in Louis Armstrong Stadium, converted her second break point in the following game before falling to the ground in celebration.
Krunic thanked the crowd for their support. “I didn’t expect you to be cheering as much for me as you did today,” she said in her post-match interview. “It was an honour for me to be on the same court as Petra. She’s a great champion. I watched both of her finals at Wimbledon. Of course, I didn’t expect to win, though I was hoping that I might win a set. Somehow I managed to win the match.”
Maria Sharapova is the clear favourite to emerge from the bottom half of the draw, particularly after the defeats of Halep and Kerber. Halep, the second seed, was beaten 7-6, 6-2 by Mirjana Lucic-Baroni, the world No 121, while Kerber, the world No 7, lost 6-1, 7-5 to the 17-year-old Swiss, Belinda Bencic.
Lucic-Baroni is through to the fourth round of a Grand Slam tournament for the first time since she reached the Wimbledon semi-finals 15 years ago. The 32-year-old did not compete in Grand Slam tournaments for seven years because of her troubled personal life. She fled to the United States from Croatia because of her abusive father, who was also her coach, and was then unable to find the financial backing to enable her to compete.
Asked about her difficulties over the years, Lucic-Baroni broke down in tears. “I’m a little bit emotional now,” she said. “I’m sorry. It’s been really hard. After so many years, to be here again, it’s incredible. I wanted this so bad. So many times I would get to a place where I could do it. Then I wanted it so bad that I’m kind of burned out. I’m so happy.”