NEW YORK, NY, USA - Unranked Tsvetana Pironkova continued her surprise US Open run with a dramatic upset over Alize Cornet, 6-4, 6-7(5), 6-3 to reach her first quarterfinal in Flushing Meadows. 

One of nine mothers competing in the singles field, Pironkova has emerged as one of the tournament’s most inspiring stories as the unranked Bulgarian, playing her first tournament after a three-year maternity leave, stunned seeded players Garbine Muguruza and Donna Vekic en route to the fourth round. 

“It's really unbelievable that I took it this far, and… that I actually managed to win four matches, and especially the last one which lasted I think about three hours,” Pironkova reflected in her post-match press conference. “So at this point, that is quite an achievement for me.”

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There was nothing to separate Pironkova and Cornet through two tight sets on Louis Armstrong Stadium, with the French player hoping to claim her first major quarterfinal berth in her 57th Grand Slam event. 

But it was 2014 Sydney champion Pironkova who emerged victorious after a nearly three-hour battle marked by marathon rallies, firing 46 winners and breaking Cornet eight times to book her spot into the quarterfinals.

“It means a lot to be here after three years of absence,” she said. “And this being my first tournament, having this great result, is something very special.”

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Pironkova and Cornet set the tone for the match early on as they traded breaks to start, with Cornet racing out to a 2-0 lead and Pironkova hitting back straight away to level. Cornet was giving Pironkova plenty of trouble throughout, covering the court and closing down points at the net. Pironkova kept Cornet under pressure, and she seemed to raise her level as the set unfolded. The Bulgarian grabbed the decisive break at 5-4 before serving out the opening set, 6-4.

Pironkova kept the momentum rolling in the second set, employing her signature inside-out backhands to great success as she opened with a break and went up 2-0. She held three break points in Cornet’s next service game as she tried to make it a double break lead, but the French player gutted out the hold and responded emphatically to reel off the next three games for a 4-2 lead. 

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Both players’ high-quality shot-making was on full display as the rallies got longer as the match went on, with Pironkova grinding out a 30-shot rally in the ninth game, 4-4, as she tried to regain control of the set. She finally broke courtesy of a Cornet double fault, and held match point as she served for the match at 5-4 - but Cornet wasn’t finished yet. 

The French player escaped from match point down as she broke Pironkova to level the set at 5-5. Cornet herself won a dramatic 40-shot rally to earn break points at 6-5, and finally broke through to take the set in a tiebreaker, 7-6(5).  

This time, it was Cornet who raced ahead to the early break, taking a 2-1 lead in the final set. But Pironkova continued to chip away at the French player’s vulnerable second serves, and was rewarded with a break straight back, 2-2. Cornet, who finished the match with nine double faults and winning only 30% of second serve points, was broken once again as Pironkova closed out the match, 6-4, 6-7(5), 6-3. 

“It was pretty tough that I didn't close the match in two sets,” Pirokonva said. “I realized I have to change something in order to survive this match, and I thought that I would start to play more aggressive so the points could be shorter. I managed to do that, and it paid off.”

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The victory earns Pironkova a chance to play the No.3 seed and former champion Serena Williams in the next round. The American took down No.15 seed Maria Sakkari in three sets earlier in the day to book a quarterfinal clash between moms.

“Definitely a tough one,” Pironkova assessed. “I played against Serena a few times. I haven't won to today. 

“Playing such a champion, such a legend of the game, it's tremendous honor, obviously. I'm really looking forward to that match, because I know the feeling is going to be very special.”