The second week of the Australian Open is under way, and the quarterfinals are beginning to take shape. Here are the key numbers and statistics from Day 7 of the tournament.

More from Day 7:

6 - Australian Open quarterfinal appearances for the last remaining former champion, Victoria Azarenka, who triumphed over Zhu Lin in a 4-6, 6-1, 6-4 barnburner. Azarenka is back in the last eight here for the first time since 2016. She fell at the quarterfinal stage in 2010 to Serena Williams, 2014 to Agnieszka Radwanska and 2016 to Angelique Kerber, but went on to take the title in 2012 and 2013.

2 - Years since the last meeting of reigning Slam champions at a Slam. In the fourth round of the 2021 Australian Open, Roland Garros winner Iga Swiatek lost to Wimbledon title holder Simona Halep 3-6, 6-1, 6-4. Two years on, as the Roland Garros and US Open reigning champion, Swiatek lost to the Wimbledon winner again, falling 6-4, 6-4 to Elena Rybakina.

The victory was Rybakina's third in her career over a Top 3 opponent, following her defeats of Karolina Pliskova in the 2020 Dubai quarterfinals and Ons Jabeur in the 2022 Wimbledon final. It was her first win over a reigning World No.1.

5 - Years since Jelena Ostapenko had last been in a major quarterfinal. Her 7-5, 6-3 defeat of Coco Gauff put her into her third overall, following Roland Garros 2017 (where she went on to the title) and Wimbledon 2018 (where she made the semifinals).

The result was Ostapenko's first Top 10 win since beating Garbiñe Muguruza in the 2022 Doha quarterfinals, first at a major since beating Karolina Pliskova in the 2020 Roland Garros second round and first of her career at a hard-court major.

1 - Rybakina and Ostapenko are the first players representing Kazakhstan and Latvia respectively to reach the last eight of the Australian Open.

5 - Jessica Pegula is now a perfect 5-0 in Grand Slam fourth rounds after defeating Barbora Krejcikova 7-5, 6-2. However, the American is 0-4 in Grand Slam quarterfinals so far in her career. Her conquerors were Jennifer Brady at the 2021 Australian Open, Ashleigh Barty at the 2022 Australian Open and Iga Swiatek at Roland Garros and the US Open 2022.

9 - Match points saved by Miriam Kolodziejova and Marketa Vondrousova in their 3-6, 7-6(9), 7-6 (12) second-round doubles victory over No.7 seeds Beatriz Haddad Maia and Zhang Shuai. Haddad Maia and Zhang held their first three match points in the second-set tiebreak, then led 5-0, 40-0 on the Czechs' serve in the decider. Kolodziejova and Vondrousova saved four in that game, and the last two in the third-set tiebreak.