The second day of main-draw action at the 2023 Australian Open saw delays for both extreme heat and torrential rain -- but plenty of players dodged the vagaries of the weather to advance to the second round. Here are the key numbers as first-round action continued.

Day 2 from the Australian Open

8 - First-round matches that were called off for the day without play beginning: No.8 seed Daria Kasatkina vs. Varvara Gracheva, qualifier Lucrezia Stefanini vs. Tatjana Maria, No.23 seed Zhang Shuai vs. Patricia Maria Tig, Mayar Sherif vs. Magda Linette, No.27 seed Irina-Camelia Begu vs. lucky loser Elizabeth Mandlik, Lucia Bronzetti vs. Laura Siegemund, No.14 seed Beatriz Haddad Maia vs. Nuria Parrizas Diaz and Sloane Stephens vs. Anastasia Potapova.

4 - First-round matches that were started, but not finished due to late evening rain. Donna Vekic leads qualifier Oksana Selekhmeteva 6-2, 2-6, 6-6 and 5-1 in the match tiebreak, having served for the match at 6-5; Lauren Davis leads Danka Kovinic 1-6, 7-5, 4-1; Claire Liu leads Madison Brengle 4-2; and Alison Riske-Amritraj leads Marketa Vondrousova 4-1.

2 - Matches that lasted 2 hours and 31 minutes, the joint-longest of the day. Moreover, they featured near-identical scorelines: wild card Kimberly Birrell upset No.31 seed Kaia Kanepi 3-6, 7-6(4), 6-1 and No.26 seed Elise Mertens scored her first win over Garbiñe Muguruza 3-6, 7-6(3), 6-1.

52 - Minutes needed for No.19 seed Ekaterina Alexandrova to defeat Ysaline Bonaventure 6-2, 6-1, the quickest match of the first round so far.

Highlights: Sabalenka d. Martincova | Mertens d. Muguruza | Townsend d. Parry | Fernandez d. Cornet | Pliskova d. Wang Xiyu | L.Fruhvirtova d. Fourlis | Garcia d. Sebov | Bencic d. Tomova | Jabeur d. Zidansek | Martic d. Golubic | Putintseva d. Cirstea

0-3 - Leylah Fernandez's Australian Open record prior to her 7-5, 6-2 win over Alizé Cornet today. The 20-year-old Canadian had lost in the first round to Lauren Davis in 2020, Elise Mertens in 2021 and Maddison Inglis in 2022. Wimbledon is now the only major where Fernandez, who reached the 2021 US Open final and 2022 Roland Garros quarterfinals, has yet to win a main draw match.

3 - Number of career Top 30 victories by Kimberly Birrell, whose win over Kaia Kanepi was an addition to her defeats of Daria Kasatkina in the 2019 Brisbane first round and Donna Vekic in the 2019 Australian Open second round. Birrell, 24, raised her ranking from No.734 to No.167 in 2022 after returning from injury; she received the wild card freed up by Venus Williams' withdrawal.

3 - Years since Anna Karolina Schmiedlova last scored a Top 30 win. The Slovak qualifier, a former World No.26, upset No.21 seed Martina Trevisan 6-3, 6-2 for her first victory over an opponent in that echelon since beating Victoria Azarenka in the second round of Roland Garros 2020.

17 - Age of Linda Fruhvirtova, the youngest player remaining in the draw. The Czech, who won her first Hologic WTA Tour title in Chennai last September, reached the second round of her second consecutive major with a 6-0, 6-4 win over wild card Jaimee Fourlis.

3 - Consecutive wins for Yulia Putintseva over Sorana Cirstea after her 2-6, 6-4, 6-3 win today. Putintseva has not lost to the Romanian since the 2017 Nürnberg quarterfinals, and leads the overall head-to-head 4-2.

Australian Open: Putintseva comes from a set down to beat Cirstea

7 - Points lost on serve by Taylor Townsend during her 6-1, 6-1 defeat of Diane Parry. After losing the first game of the match, Townsend won 11 straight games before Parry got on the board again.

8 - Matches that Garbiñe Muguruza has lost from a set up in the past 12 months: to Veronika Kudermetova in Dubai, Alison Riske-Amritraj in Indian Wells, Yulia Putintseva in Rome, Martina Trevisan in Rabat, Kaia Kanepi at Roland Garros, Petra Kvitova at the US Open, Bianca Andreescu at Adelaide 1 and Elise Mertens today at the Australian Open.

0 - Tamara Zidansek's number of Top 50 wins since her run to the 2021 Roland Garros semifinals. The Slovenian came within a set of rectifying this against No.2 seed Ons Jabeur, but fell 7-6(8), 4-6, 6-1.