Tsvetana Pironkova, playing in her first event since 2017, claimed one of the shock upsets at the US Open on Thursday by dispatching double Grand Slam winner Garbine Muguruza 7-5, 6-3 to move into the third round at Flushing Meadows.

After three years away from the WTA Tour following the birth of her son Alexander, the unranked Bulgarian had 10th-seeded Muguruza smashing her racket and mumbling in frustration as the Spaniard’s US Open jinx continued to haunt her.

Australian Open champion Sofia Kenin used a mix of power and sharp angles to overwhelm Canadian Leylah Fernandez 6-4, 6-3 to reach the third round.

The second-seeded Kenin won 76% of her first-serve points and unleashed a barrage of accurate shots from the baseline that were too much to handle for Fernandez.

Up next for Kenin, who has never been past the third round in New York, will be Tunisian 27th seed Ons Jabeur, who beat Estonia’s Kaia Kanepi 7-6 (8) 6-0.

On Wednesday, top seed Karolina Pliskova suffered a shock 6-1, 7-6 (7-2) loss to Frenchwoman Caroline Garcia in the second round to blow the women’s draw wide open.

Pliskova, a former world No.1 had no answer to Garcia’s power and precision as the Frenchwoman raced out of the blocks to open up a 5-0 lead in the opening set.

The Czech was helpless in the face of her unseeded opponent’s relentless onslaught and her exit marked the worst performance by a women’s top seed in New York since Simona Halep’s opening round defeat in 2018.

Among men, world No. 1 Novak Djokovic brushed aside Briton Kyle Edmund 6-7 (5-7) 6-3, 6-4, 6-2 after a sluggish start to remain unbeaten in 2020 and move into the third round.

On a hot, humid day at Flushing Meadows, Edmund was left bathed in sweat while a cool and collected Djokovic stayed on course for his 18th Grand Slam title and improved his 2020 match record to 25-0. “Mentally, Kyle played a fantastic first set, did not do much wrong,” said Djokovic, who celebrated his victory by moving to the centre of the court and acknowledging the canned applause.

Fifth seed Alexander Zverev fought off a spirited challenge from American wildcard Brandon Nakashima to claim a 7-5, 6-7 (8-10), 6-3, 6-1 victory in the second round.

Zverev did not drop serve in a solid all-round display but was stretched to four sets by teenager Nakashima, ranked 223 in the world.

Stefanos Tsitsipas weathered a serve-volleying storm from Maxime Cressy before grinding the American wildcard down 7-6 (7-2), 6-3, 6-4 to reach the third round.

In a slow-burning contest of short, sharp points, fourth seed Tsitsipas had to fight off a set point against the French-born Cressy, who fired 21 aces and rushed the net 92 times on a muggy night at Arthur Ashe Stadium.

Denis Shapovalov blew hot and cold as he was twice forced to come from behind to beat Kwon Soon-woo 6-7(5), 6-4, 6-4, 6-2 and secure a place in the third round.

The 12th seed was in all sorts of trouble against the unheralded South Korean, losing the first set in a tie-break and going 4-2 down in the third after leveling up the contest.

Divij, Cacic exit

India’s Divij Sharan and his Serbian partner Nikola Cacic fought hard before going down in three sets to eighth seeds Nikola Mektic and Wesley Koolhof in the first round of men’s doubles. Sharan and Cacic lost 4-6, 6-3, 3-6 against Croatia’s Mektic and Koolhof of the Netherlands in a tough contest that lasted one hour and 46 minutes.