New York - Reigning US Open champion Naomi Osaka swept into the third round while Alexander Zverev clawed through another five-set marathon Thursday, but Petra Kvitova crashed out as organizers sought to play catch up following heavy rain.
Top seed Osaka proved too strong for 53rd-ranked Magda Linette of Poland, sweeping to a 6-2, 6-4 victory and setting up a potential showdown with 15-year-old American sensation Coco Gauff for a spot in the last 16.
Twenty-two singles ties were pushed back from Wednesday after a steady downpour limited play to the two principal show courts in New York, beefing Thursday's schedule up to 54 matches across both halves of the singles draws.
Osaka wrapped up the opening set against last week's WTA Bronx champion Linette in 30 minutes but endured a brief wobble, falling 3-0 down in the second, before reeling off six of the final seven games to advance.
"I'm really happy to not have to play a three-set match," Osaka said.
Among the celebrities watching her match at Louis Armstrong Stadium were basketball legend Kobe Bryant and former NFL quarterback Colin Kaepernick, whose kneeling protest became a national symbol for objecting to racial inequality and social injustice.
"I'm really grateful they came out," Osaka said. "It's really cool. I honestly just wanted to finish as fast as possible because I didn't want them to be out in the sun too long."
Osaka awaits the winner between teenager Gauff, the world number 140 who reached the fourth round in July at Wimbledon, or 112th-ranked Hungarian qualifier Timea Babos.
Gauff can become the youngest woman to reach the last 32 in New York since Anna Kournikova in 1996.
Sixth seed Zverev survived a second successive five-set battle as he outlasted American Frances Tiafoe 6-3, 3-6, 6-2, 2-6, 6-3.
Germany's Zverev was taken the distance by Radu Albot in his opening match and 45th-ranked Tiafoe forced him into another decider before last year's ATP Finals champion battled through to round three to equal his best US Open run.
"I've been here before. It's usually what I do in the first few rounds of majors, to play five sets," said Zverev, who has featured in 11 five-set matches at Grand Slams since the start of 2018 -- more than any other player.
"Frances gave me another fight and I had to go five sets because he took everything out of me."
Andrea Petkovic knocked out Czech sixth seed Kvitova, a two-time Wimbledon champion, to reach the women's third round for the first time since 2015.
German world number 88 Petkovic, whose best US Open showing was a 2011 quarter-final run, strung together successive main draw wins for just the second time this season in a 6-4, 6-4 triumph.
"I've beaten her before in Grand Slams and big matches. That gave me the belief. That's the most important part if you want to win," said Petkovic, who next faces Belgian 25th seed Elise Mertens.
"She really played a good game. I don't think I played that badly. I did have my chances, for sure, but somehow I just couldn't make it," Kvitova said.
Fifth seed Daniil Medvedev, who owns an ATP-best 45 wins this season, was to face Bolivia's Hugo Dellien, having arrived in New York on the back of a maiden Masters title in Cincinnati and runner-up finishes in Montreal and Washington.
Three-time US Open winner Rafael Nadal takes on Australian wildcard Thanasi Kokkinakis in the evening session at Arthur Ashe Stadium, where reigning Wimbledon champion Simona Halep was due to face American Taylor Townsend in the afternoon.
Nick Kyrgios, who again landed himself in hot water after calling the ATP "corrupt" following his first-round win, meets 104th-ranked Frenchman Antoine Hoang.
Britain's Dan Evans took out French 25th seed Lucas Pouille in four sets to book a clash with five-time US Open champion Roger Federer, while Denis Kudla awaits world number one Novak Djokovic after the American beat 27th seed Dusan Lajovic of Serbia.
US Open results on Thursday (x denotes seeding):
Denis Kudla (USA) bt Dusan Lajovic (SRB x27) 7-5, 7-5, 0-6, 6-3
Stanislas Wawrinka (SUI x23) bt Jeremy Chardy (FRA) 6-4, 6-3, 6-7 (3/7), 6-3
Paolo Lorenzi (ITA) bt Miomir Kecmanovic (SRB) 7-6 (13/11), 6-7 (2/7), 7-6 (7/2), 3-6, 6-3
Nikoloz Basilashvili (GEO x17) bt Jenson Brooksby (USA) 3-6, 7-6 (7/3), 7-5, 6-2
Feliciano Lopez (ESP) bt Yoshihito Nishioka (JPN) 6-7 (7/9), 6-0, 6-4, 6-4
Daniil Medvedev (RUS x5) bt Hugo Dellien (BOL) 6-3, 7-5, 5-7, 6-3
Daniel Evans (GBR) bt Lucas Pouille (FRA x25) 6-4, 6-3, 6-7 (4/7), 6-4
Pablo Carreno-Busta (ESP) bt Ricardas Berankis (LTU) 6-4, 6-7 (3/7), 6-2, 6-0
David Goffin (BEL x15) bt Gregoire Barrere (FRA) 6-2, 6-2, 6-2
Kamil Majchrzak (POL) bt Pablo Cuevas (URU) 6-7 (3/7), 6-4, 2-6, 6-4, 6-1
Alex De Minaur (AUS) bt Christian Garin (CHI x31) 6-3, 7-5, 6-3
Andrey Rublev (RUS) bt Gilles Simon (FRA) 6-2, retired
Nick Kyrgios (AUS x28) bt Antoine Hoang (FRA) 6-4, 6-2, 6-4
Matteo Berrettini (ITA x24) bt Jordan Thompson (AUS) 7-5, 7-6 (7/5), 4-6, 6-1
Alexei Popyrin (AUS) bt Mikhail Kukushkin (KAZ) 2-6, 7-5, 6-3, 6-2
Gael Monfils (FRA x13) bt Marius Copil (ROU) 6-3, 6-2, 6-2
Denis Shapovalov (CAN) bt Henri Laaksonen (SUI) 6-4, 7-6 (7/2), 6-2
Pablo Andujar (ESP) bt Lorenzo Sonego (ITA) 6-2, 6-4, 6-2
Alexander Bublik (KAZ) bt Thomas Fabbiano (ITA) 6-7 (3/7), 5-7, 6-4, 6-3, 6-3
Alexander Zverev (GER x6) bt Frances Tiafoe (USA) 6-3, 3-6, 6-2, 2-6, 6-3
Aljaz Bedene (SLO) bt Benoit Paire (FRA x29) 4-6, 6-7 (3/7), 6-2, 7-5, 7-6 (7/4)
Diego Schwartzman (ARG x20) bt Egor Gerasimov (BLR) 6-4, 6-2, 6-0
Tennys Sandgren (USA) bt Vasek Pospisil (CAN) 6-3, 6-7 (4/7), 6-3, 6-4
John Isner (USA x14) bt Jan-Lennard Struff (GER) 6-3, 7-6 (7/4), 7-6 (7/5)
Marin Cilic (CRO x22) bt Cedrik-Marcel Stebe (GER) 4-6, 6-3, 7-5, 6-3
Chung Hyeon (KOR) bt Fernando Verdasco (ESP x32) 1-6, 2-6, 7-5, 6-3, 7-6 (7/3)
Rafael Nadal (ESP x2) bt Thanasi Kokkinakis (AUS) walkover
Naomi Osaka (JPN x1) bt Magda Linette (POL) 6-2, 6-4
Coco Gauff (USA) bt Timea Babos (HUN) 6-2, 4-6, 6-4
Anett Kontaveit (EST x21) bt Ajla Tomljanovic (AUS) 4-6, 7-5, 6-2
Belinda Bencic (SUI x13) bt Alize Cornet (FRA) 6-4, 1-6, 6-2
Yulia Putintseva (KAZ) bt Aryna Sabalenka (BLR x9) 6-3, 7-6 (7/3)
Donna Vekic (CRO x23) bt Kaia Kanepi (EST) 7-5, 6-3
Julia Goerges (GER x26) bt Francesca Di Lorenzo (USA) 7-5, 6-0
Kiki Bertens (NED x7) bt Anastasia Pavlyuchenkova (RUS) 7-5, 6-4
Taylor Townsend (USA) bt Simona Halep (ROU x4) 2-6, 6-3, 7-6 (7/4)
Sorana Cirstea (ROU) bt Aliona Bolsova (ESP) 3-6, 6-4, 6-2
Caroline Wozniacki (DEN x19) bt Danielle Collins (USA) 4-6, 6-3, 6-4
Bianca Andreescu (CAN x15) bt Kirsten Flipkens (BEL) 6-3, 7-5
Kristie Ahn (USA) bt Anna Kalinskaya (RUS) 6-2, 6-3
Jelena Ostapenko (LAT) bt Alison Riske (USA) 6-4, 6-3
Elise Mertens (BEL x25) bt Kristyna Pliskova (CZE) 6-2, 6-2
Andrea Petkovic (GER) bt Petra Kvitova (CZE x6) 6-4, 6-4
Dayana Yastremska (UKR x32) bt Rebecca Peterson (SWE) 6-4, 6-1
Sofia Kenin (USA x20) bt Laura Siegemund (GER) 7-6 (7/4), 6-0
Johanna Konta (GBR x16) bt Margarita Gasparyan (RUS) 6-1, 6-0
Zhang Shuai (CHN x33) bt Ekaterina Alexandrova (RUS) 7-6 (7/5), 4-6, 6-3
Ons Jabeur (TUN) bt Aliaksandra Sasnovich (BLR) 3-6, 6-4, 6-2
Karolina Muchova (CZE) bt Hsieh Su-Wei (TPE x29) 6-1, 4-6, 7-6 (7/2)
Petra Martic (CRO x22) bt Ana Bogdan (ROU) 6-2, 6-4
Anastasija Sevastova (LAT x12) bt Iga Swiatek (POL) 3-6, 6-1, 6-3
Fiona Ferro (FRA) bt Kristina Mladenovic (FRA) 6-4, 6-7 (3/7), 6-3
Wang Qiang (CHN x18) bt Alison Van Uytvanck (BEL) 7-5, 6-4
Maria Sakkari (GRE x30) bt Peng Shuai (CHN) 6-7 (5/7), 6-4, 6-2