US Open Day 2 by the numbers: Zheng's ace record, Pliskova's tiebreaks and more

The first round of the 2022 US Open is (almost) done and dusted. Here are some of the key numbers and statistics from Day 2.

US Open Day 2: Alizé Cornet ends Emma Raducanu's title defense | Danielle Collins ousts Naomi Osaka | Alison Van Uytvanck defeats Venus Williams | Sloane Stephens wins | Iga Swiatek and the Top 10 roundup | Andrea Petkovic retires | Getting to know Daria Snigur

Scores | Order of play | Draw

21 - The number of aces fired by Zheng Qinwen during her 6-3, 3-6, 6-4 upset of No.16 seed Jelena Ostapenko. Zheng has broken her own 2022 record for aces in a single match (previously the 19 she hit against Ekaterina Alexandrova in Charleston), and her tally is also the joint second-highest number in a single WTA match at the US Open since records began to be kept in 1991.

Only Karolina Pliskova, who totaled 24 in defeating Amanda Anisimova 7-5, 6-7(5), 7-6(7) in the 2021 second round, has served more. Julia Goerges also fired 21 aces in her 2019 fourth-round loss to Donna Vekic 6-7(5), 7-5, 6-3.

The match was the 19-year-old Zheng's US Open debut, and her third Top 20 win of 2022.

7 - Consecutive deciding tiebreaks won by Karolina Pliskova. The No.22 seed came from 4-1 down in the third set to survive Magda Linette 6-2, 4-6, 7-6[8], sealing the win in the first super-tiebreak of her singles career. Former US Open finalist Pliskova has not lost a deciding tiebreak since the 2019 Birmingham second round, where she was defeated 6-2, 3-6, 7-6(7) by twin sister Kristyna.

Since then, she has won them over Jelena Ostapenko at Rome 2021; Donna Vekic at Montréal 2021; Amanda Anisimova at the US Open 2021; Garbiñe Muguruza at the WTA Finals 2021; Petra Kvitova at Stuttgart 2022; and Bianca Andreescu at Berlin 2022.

89 - Paula Badosa's winning percentage in tiebreaks over the past 52 weeks. The No.4 seed improved this number again with her 3-6, 7-6(4), 6-3 win over Lesia Tsurenko. Badosa has won 20 out of 22 tiebreaks dating back to her 6-3, 7-6(4) win over Iga Swiatek in the second round of the Tokyo Olympic Games last year. Since then, only Belinda Bencic (in Charleston) and Aryna Sabalenka (in Stuttgart) have won tiebreaks against the Spaniard.

18 - Bagel sets dished out by Iga Swiatek in 2022 so far. The World No.1 added to her total with a 6-3, 6-0 defeat of Jasmine Paolini. Only Serena Williams, who won 25 sets 6-0 in 2013, has won more in a single season since 2000.

18 - Consecutive Grand Slam third rounds reached by Elise Mertens between the 2018 Australian Open and Wimbledon 2022. The No.32 seed's streak was ended after Irina-Camelia Begu won their first round 3-6, 6-2, 6-3, reeling off six straight games from 2-0 down in the second set and five straight games from 3-1 down in the third. Begu had been winless in three previous meetings with Mertens, including in the second round of this year's Australian Open.

63 - The all-time record for consecutive Grand Slam main draw appearances, set by Alizé Cornet in her 6-3, 6-3 victory over defending champion Emma Raducanu. Cornet had not missed a major since qualifying for the 2007 Australian Open as a 17-year-old, losing to Daniela Hantuchova in the first round. Previously, she had been tied at 62 appearances with Ai Sugiyama.

91 - The all-time record for overall Grand Slam main draw appearances, extended by Venus Williams in her 6-1, 7-6(5) loss to Alison Van Uytvanck. Venus made her major debut as a 17-year-old at Roland Garros 1997, defeating Naoko Sawamatsu 6-2, 6-7(2), 7-5 in the first round before falling 5-7, 6-3, 7-5 to Nathalie Tauziat in the second.

3:12 - The length of the longest match of Day 2, and of the tournament so far. Lauren Davis advanced leading 4-6, 7-6(3), 5-4 and serving for the match at 30-30 when Lucia Bronzetti was forced to retire due to cramping.

28 - The length of the longest rally of Day 2, and of the tournament so far, won by Lesia Tsurenko at 3-3, deuce in the first set of her clash with Paula Badosa. The Ukrainian won it -- and thereafter the game and the first set -- when Badosa sent a forehand wide.

0-5 - Clara Burel's record against Top 30 opposition prior to breaking that duck with a 6-4, 6-4 upset of Wimbledon champion Elena Rybakina. Burel's season record ahead of the US Open was just 9-20 (5-11 at WTA main draw level), but the Frenchwoman has now won four in a row after backing up a successful qualifying campaign with a career-best victory.

0-5 - The deficit overturned by Petra Martic in the second set against Varvara Gracheva. The Croat saved one set point serving at 3-5 and ultimately came through 6-4, 7-6(3).

29 - Matches won by Bernarda Pera in July and August. The American surged from No.130 to a career-high of No.45 in the space of seven weeks after winning her first two Hologic WTA Tour titles in Budapest and Hamburg, then reaching the Concord 125 final and the Cleveland semifinals. However, Pera's hot streak came to an end in the first round of the US Open with a 6-4, 6-4 loss to Anhelina Kalinina.

17 - Former Grand Slam semifinalists remaining in the draw, 10 of whom have previously reached the last four at the US Open. Each quarter still contains at least one player who has reached the final at Flushing Meadows: Sloane Stephens (first quarter), Victoria Azarenka and Karolina Pliskova (second quarter), Madison Keys and Bianca Andreescu (third quarter), Leylah Fernandez and Serena Williams (fourth quarter).

4 - Teenagers remaining in the draw. Thirteen had started in the main draw; Coco Gauff and Leylah Fernandez were the only victors on Day 1. They were joined on Day 2 by Zheng Qinwen and the youngest player left, 17-year-old qualifier Linda Fruhvirtova. The Czech defeated Wang Xinyu 6-3, 6-4 on her Grand Slam main draw debut.

Elsewhere, 17-year-old Linda Noskova fought back from a 5-2 second-set deficit before losing 6-2, 6-7(3), 6-2 to Czech compatriot Marie Bouzkova; and 18-year-old Erika Andreeva led No.21 seed Petra Kvitova 5-2 before falling 7-6(3), 6-0.

3 - Players sealing their first Grand Slam main draw win on Day 2. Along with Fruhvirtova, there were victories for fellow qualifiers Cristina Bucsa 6-4, 6-4 over Kaja Juvan, and Yuan Yue 6-3, 6-2 over Jaimee Fourlis. Bucsa had been 0-3 in Grand Slam main draws since making her debut at the 2021 US Open.

1 - First-round match still to be completed. No.28 seed Ekaterina Alexandrova led wild card Peyton Stearns 6-4, 4-6, 4-3, having just broken serve in the deciding set, when rain forced play to be abandoned. Should Stearns come back to win when they resume on Day 2, she will join the ranks of first-time Grand Slam winners.