No.6 seed Belinda Bencic has been facing off against Jelena Ostapenko since their U14 days, with Ostapenko leading the overall head-to-head 4-1, including 1-0 at pro level. The Class of 1997 peers first met in the 2011 Les Petits As semifinals, with the Latvian winning 6-1, 6-4 en route to the title; in ITF junior competition, they split two meetings, with Bencic winning 1-6, 6-4, 6-2 on clay in the 2011 Prague Grade 2 event and Ostapenko taking their 2012 Repentigny Grade 1 meeting on hard courts 0-6, 7-5, 6-3. It would be six years before they met again: Ostapenko, now the World No.6, would triumph 6-4, 3-6, 6-1 in the second round of Indian Wells 2018, Bencic's last match before a two-month injury break.

Laura Siegemund, who overcame a 0-5 head-to-head against CoCo Vandeweghe to beat the American in the first round, defeated No.2 seed Karolina Pliskova 7-6(3), 5-7, 6-3 in their only previous meeting in the 2017 Stuttgart quarterfinals - one of three Top 10 scalps for the German en route to the biggest title of her career. However, just one of Siegemund's nine total Top 10 wins has come on hard courts - and it was via retirement over Timea Bacsinszky in the first round of Luxembourg 2015. Brisbane champion Pliskova has come into her fourth major in the past five on a winning streak from capturing a warm-up title, but has lost to an opponent outside the Top 10 in six of her last seven Grand Slams, and 13 of the 17 majors since she first cracked the Top 10 herself.

Former World No.1 Garbiñe Muguruza is tied at 1-1 against Ajla Tomljanovic. The 2017 quarterfinalist squandered a 6-3, 5-2 lead in losing to Tomljanovic 3-6, 7-6(6), 6-1 in the second round of Miami 2014, but closed her out 6-3, 6-0 in last year's Monterrey quarterfinals en route to Muguruza's most recent title. Home favorite Tomljanovic is bidding to make the third round of a major for the second time in her career following her last-16 run at Roland Garros 2014.

Three of today's slated matches will reprise a contest from the first two weeks of the 2020 season. One of those is No.16 seed Elise Mertens' clash with Heather Watson: Mertens had been undefeated against Watson in three meetings before this year, but the Hobart quarterfinals last week saw the Briton post her first Top 20 win since Wimbledon 2017 with a 6-7(5), 6-4, 7-5 upset of the Belgian in three hours and 33 minutes - the longest match of the year to date.

The seventh-longest WTA main draw match of 2020 so far will also be reprised today, Zarina Diyas's dramatic 6-1, 6-7(9), 6-4 victory over Anna Blinkova in the second round of Shenzhen. That result extended the Kazakh's head-to-head lead to 3-1, and she will seek to reach the Australian Open third round for the first time since making that stage in her first two appearances here in 2014-15.

Heather Watson won the longest match of 2020 so far over Elise Mertens in the Hobart quarterfinals last week.

Photo by Getty

No.26 seed Danielle Collins's 6-1, 6-0 defeat of Yulia Putintseva in the second round of Adelaide last week was one of several eye-catchingly dominant scorelines the in-form American has posted in 2020. Their head-to-head is tied at 1-1, with Putintseva having won their first meeting in Eastbourne last year via retirement.

Zarina Diyas and Yulia Putintseva are bidding to join Kazakh No.1 Elena Rybakina in the third round. A win for one would mark the third time that two Kazakhs have reached that stage of a major - Diyas and Yaroslava Shvedova accomplished this at both Wimbledon 2014 and the 2015 Australian Open - while a win for both would mark the first time that three Kazakhs have made the third round of a Grand Slam ever.

Alizé Cornet defeated No.19 seed Donna Vekic 6-3, 6-4 in their sole prior encounter, in the second round of Monterrey 2017. All four of Auckland quarterfinalist Cornet's wins in 2020 have come over three sets.

Former World No.35 Catherine Bellis, playing her fourth tournament back after being sidelined for 17 months due to four wrist surgeries, is bidding to make the third round of a Grand Slam for the third time in her career, and first since Roland Garros 2017. An upset of No.20 seed Karolina Muchova would be the 20-year-old American's first Top 30 win since defeating Elise Mertens at Dubai 2018.

No.5 seed Elina Svitolina has dropped just one set to Lauren Davis in four previous meetings, with the toughest of those being her 6-1, 4-6, 6-3 win the second round of the 2016 US Open. The Ukrainian has lost just 15 games across their other three encounters, with the most recent being a 6-0, 6-4 win in the 2017 Dubai quarterfinals.

Former World No.2 Svetlana Kuznetsova snapped a streak of six consecutive Grand Slam first-round exits with her upset of No.15 seed Marketa Vondrousova, and will now bid to reach the third round of a major for the first time since her 2017 Roland Garros quarterfinal run. The Russian holds a 2-0 lead over Camila Giorgi, with both matches coming in 2014 - winning 7-6(5), 6-3 in the second round of Roland Garros and 6-4, 6-7(4), 6-3 in the first round of Cincinnati.



Click here to view the Day 4 order of play.


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