NEW YORK, New York -- After a blockbuster Day 1 at the US Open, which saw No.3 Naomi Osaka begin her title defense, Day 2 sees top seed Ashleigh Barty and 2019 champion Bianca Andreescu get underway. 

Click here for the full order of play.

Here are the matches that we circled when the draw came out:

[1] Ashleigh Barty vs. Vera Zvonareva (2nd match, Ashe)

The top seed gets her campaign underway against the 2010 finalist Vera Zvonareva. The Russian veteran has worked her way up to a ranking of No.101 over the last few seasons after coming back from maternity leave. Since defeating Petra Kvitova at the Italian Open in May, Zvonareva has not defeated a Top 50 opponent. But her ability to redirect the ball down the line and into the corners is unrivaled when she is on. 

Head-to-head: First meeting

Preview stat: Barty is tied for second on tour for most three-set wins this season, tallying 14 so far.

READ: Barty, Osaka, Andreescu, Sabalenka meet the press

[6] Bianca Andreescu vs. Viktorija Golubic (2nd night match, Ashe)

The 2019 champion gets a stern opening test against one of the most improved players of 2021 in Switzerland's Viktorija Golubic. Bianca Andrreescu told reporters before the tournament that's she's feeling healthy and has put the toe issue that bothered her in Montreal and Cincinnati behind her. Armed with veteran coach Sven Groeneveld at her side, a healthy Andreescu is more than capable of showing the hard-court form she stunned the tour with in 2019. She just needs matches to build her rhythm. 

Against Golubic, Andreescu will be facing an aggressive baseliner who can dazzle with her one-handed backhand. The Swiss is having a career season, having made back-to-back hardcourt finals in Lyon and Monterrey in the spring, capturing a WTA 125 title in Saint Malo, and making her first major quarterfinal at Wimbledon over the summer. She followed that up with a silver medal run in doubles with Belinda Bencic. Along with Cincinnati finalist Jil Teichmann and Gold Medalist Bencic, oit's been a summer of Swiss excellence on the WTA Tour. This is a prime opportunity for Golubic to ride the wave to an upset.

Head-to-head: First meeting

Preview stat: Golubic began the season ranked No.136 and is up to a career-high No.45.

[17] Maria Sakkari vs. Marta Kostyuk (1st match, Court 10)

A year ago, Marta Kostyuk led eventual champion Naomi Osaka by a break in the third set before Osaka climbed back to win 6-3, 6-7, 6-2 in the third round. In May, the 19-year-old Ukrainian gave defending champion Iga Swiatek a tough test in the Round of 16. Kostyuk has been a name to watch ever since she had a breakout run at the 2018 Australian Open, where she made the third round as a qualifier at 15.

For 17th seeded Maria Sakkari, rhythm and form have been tough to find since she had match points on Barbora Krejcikova in the Roland Garros semifinals, losing 9-7 in the third. She is 5-4 since, though her last three losses came quality opposition in Elina Svitolina (Olympics), Victoria Azarenka (Montreal), and Angelique Kerber (Cincinnati). She'll need to get her serve going against Kostyuk, who loves to be aggressive off the return.

Head-to-head: First meeting

Preview stat: After making the quarterfinals in Chicago last week, Kostyuk is up to a career-high ranking of No.55.

[22] Karolina Muchova vs. Sara Sorribes Tormo (4th match, Court 6)

Karolina Muchova is a Grand Slam juggernaut, while Sara Sorribes Tormo is in the midst of a career season. Muchova has already made the Australian Open semifinals and a second Wimbledon quarterfinal this season, while posting her best result at the US Open last fall, progressing to the Round of 16. In contrast, No.41 Sorribes Tormo has been a consistent force at the tour level but has yet to win back-to-back matches in her career at a Slam. The Spaniard comes into New York off a strong hardcourt summer. She defeated Barty at the Olympics and made the quarterfinals in Montreal and semifinals in Cleveland. 

On form, Sorribes Tormo has the edge. But there's just something about the Czech at Slams.

Head-to-head: Sorribes Tormo leads, 1-0.

Preview stat: Muchova is 11-3 at the Slams in 2021. She is 7-5 outside of the Slams.

Emma Raducanu vs. Stefanie Voegele (2nd match, Court 17)

The 18-year-old Brit who dazzled en route to the Round of 16 in her Wimbledon debut has had a strong American summer. She made the final of the WTA 125 in Chicago (l. Tauson) and did not drop a set in her three qualifying matches to earn a spot in her first US Open main draw. Still ranked at No.150, Raducanu has played with great poise and has a technically solid game that seems suited for the long haul. 

READ: Out of the spotlight, Raducanu engineers surge in the U.S.

She'll face Switzerland's Stefanie Voegele, who is into the main draw as a lucky loser after 2020 semifinalist Jennifer Brady was forced to withdraw due to injury. The 31-year-old reached a career-high No.42 in 2013, but is down to No.128. 

Head-to-head: First meeting

Preview stat: Voegele has not defeated a Top 150 player since beating Heather Watson in Madrid qualifying in April.

[23] Jessica Pegula vs. Anastasia Potapova (5:00 pm, Court 17)

The US Open could be a great showcase for Jessica Pegula's outstanding 2021 season. The Buffalo-native has made the Round of 16 or better at seven consecutive hardcourt events on tour, starting with her quarterfinal run at the Australian Open. Her best result at the US Open is a third-round appearance last year, but she comes in this year after making her first WTA 1000 semifinal in Montreal and a Round of 16 showing in Cincinnati. 

Head-to-head: Pegula leads, 1-0. 

Preview stat: In their only prior meeting, Potapova took Pegula to a deciding tiebreak which the American won 6-2, 6-7(3), 7-6(6) in Dubai qualifying. 

[29] Veronika Kudermetova vs. Sorana Cirstea (3rd match, Court 14)

When Russia's Veronika Kudermetova meets Sorana Cirstea on Tuesday, it will be on of the more evenly-matched ties of the first round. Kudermetova started her 2021 season with a strong run on hardcourts to the Abu Dhabi final and then won her first WTA title on the quick green clay of Charleston. Cirstea has proven herself a danger at the Slams over the last two seasons, having made the third round or better in four of her last five majors, including a run to the Round of 16 at Roland Garros this year. In each of those runs, she knocked out a seed in the first week. 

Head-to-head: Cirstea leads, 1-0

Preview stat: Cirstea is 6-2 vs. the Top 20 this season. 

Clara Tauson vs. Clara Burel (2nd match, Court 6)

It's an all-Clara battle here of former Junior No.1s here, as 18-year-old Danish phenom Clara Tauson takes on 20-year-old Clara Burel of France. Tauson is in great form after winning the WTA 125 in Chicago, defeating Raducanu in the final, and having won her first tour-level title earlier in the year in Lyon. 

Head-to-head: Tauson leads, 2-0

Preview stat: At No.74, Tauson is the second-youngest teenager in the Top 100 behind Coco Gauff. 

Liudmila Samsonova vs. Katie Boulter (4th match, Court 9)

After a breakout grass season that saw win her first WTA title in Berlin as a qualifier and advance to her first Round of 16 at a Slam in her Wimbledon debut, Liudmila Samsonova is up to a career-high No.52 after starting the season well outside the Top 100. Three weeks ago in Montreal, she ousted Elena Rybakina in the first round. 

Boulter played one of the best matches of Wimbledon, pushing Aryna Sabalenka in a 4-6, 6-3, 6-3 effort. The Brit has already played three matches in qualifying, winning 6-4 in the third in back-to-back matches to secure her US Open main draw debut.  

Head-to-head: First meeting

Preview stat: Since the start of Berlin, Samsonova has not lost to a player ranked outside the Top 50.