For the second year running, the No.2 seed faces a former US Open champion in the first round. Last year, Maria Sharapova upset Simona Halep at the first hurdle; this year, 2011 victor Samantha Stosur goes up against Australian Open champion Caroline Wozniacki. The Dane leads the head-to-head 7-5, including their most recent meeting at Wuhan 2016 and five of the pair's last six completed matches. Stosur, however, leads 4-2 on outdoor hard courts; the Australian's last full victory over Wozniacki was a 6-4, 7-6(9) win in the second round of Beijing in 2014, as well as a win via retirement at Washington 2016. Stosur is bidding for her first Top 3 win since defeating Victoria Azarenka in the 2013 Carlsbad final.

Petra Kvitova and Yanina Wickmayer resume a rivalry that is currently all square at 4-4, with five of those meetings going to three sets (on each of those occasions, the victor was the player who lost the first set). It is their first meeting on outdoor hard courts in nine years: their third encounter was in the fourth round of the 2009 US Open, a breakthrough tournament for both 19-year-old players. Kvitova was coming off her maiden victory over a World No.1 after beating Dinara Safina in the third round to make the second week of a major for the second time - but fell 4-6, 6-4, 7-5 to Wickmayer, who went on to make her first and so far only Grand Slam semifinal. Their most recent meeting overall was in the second round of Eastbourne in 2013, which the Belgian also won 3-6, 6-4, 7-5 - the same tournament in which she scored her most recent Top 10 win, over Maria Kirilenko in the quarterfinals.

Former World No.9 Andrea Petkovic has not been ranked above No.87 at any point this year - but the German has been a giant-killer in majors, scalping a seed in the first round of each Slam so far. Today, she has an opportunity to add No.10 seed Jelena Ostapenko to Petra Kvitova at the Australian Open, Kristina Mladenovic at Roland Garros and Zhang Shuai at Wimbledon. The Latvian has gone winless in two tournaments since her Wimbledon semifinal run; in her only previous encounter with Petkovic in the 2016 Doha semifinals, she was a winner via retirement.

Maria Sharapova and Patty Schnyder shake hands after their 2007 Roland Garros quarterfinal, in which the Russian saved two match points to triumph 3-6, 6-4, 9-7 (Getty)

Throwback Tuesday comes in the form of the first-round matchup between 2006 champion Maria Sharapova and 39-year-old Patty Schnyder, the oldest player to come through Grand Slam qualifying in the Open Era. The Russian was the victor on seven of their previous eight encounters between 2004 and 2008, with Schnyder's sole win coming in the 2005 Rome semifinals, 3-6, 6-3, 6-1. However, five of Sharapova's victories were over three sets, including a classic Roland Garros quarterfinal in 2007 in which she saved two match points to triumph 3-6, 6-4, 9-7, and their most recent match in the 2008 Rome quarterfinals, won 6-7(3), 7-5, 6-2 by the former World No.1. Today, Schnyder will be shooting for her first Top 30 win since defeating Ana Ivanovic in the first round of Dubai 2011, while Sharapova will be aiming to preserve her unbeaten record in US Open first rounds.

In Naomi Osaka's 10 Slam main draws to date, the No.20 seed has reached at least the third round eight times - including at both her previous US Opens - and only lost in the first round once. The Japanese No.1 will seek to preserve that trend against Laura Siegemund, whom she beat for the first time in three attempts in the second round of Charleston this May - the German's first WTA tournament back from a knee injury that kept her sidelined for 10 months.

Three winners from the US Open Series warm-up events are in action today: San Jose champion Mihaela Buzarnescu, Cincinnati champion Kiki Bertens and New Haven champion Aryna Sabalenka. Two players have triumphed at both Cincinnati and the US Open in the same year, Kim Clijsters in 2010 and Serena Williams in 2014; the New Haven-New York double has also been achieved twice, by Venus Williams in 2000 and 2001. In San Jose's previous location at Stanford, 15 champions in the Open Era have gone on to win in Flushing Meadows, most recently Serena Williams in 2014.

2003 US Open girls' champion Kirsten Flipkens (Getty)

A first-round clash of former junior champions takes place between No.24 seed CoCo Vandeweghe, who defeated Kristina Mladenovic and Gabriela Paz to lift the girls' trophy in 2008, and Kirsten Flipkens, whose 2003 title run included wins over Vania King, Kateryna Bondarenko and Michaella Krajicek. Vandeweghe has won both of their previous matches, in the second round of Auckland in 2015 and the first round of Doha the following year; last year's semifinalist will be seeking to snap a five-match losing streak stretching back to the 's-Hertogenbosch semifinals in June.

Wildcard Amanda Anisimova has made a splash in 2018 despite being kept out of action for three-and-a-half months with an ankle injury; the 16-year-old's victory over Petra Kvitova in Indian Wells means that she is the youngest player to currently own a Top 10 win, and she has compiled a 7-3 record in WTA main draws. Today, she has a chance for revenge against Taylor Townsend, the player who beat her 2-6, 6-2, 6-3 on her WTA debut last year in Miami.

Former World No.9 Timea Bacsinszky will seek to score her first match win since Wimbledon 2017 against Aleksandra Krunic today. The Swiss player has been beset by hand and leg injuries for over a year and has gone winless in seven matches so far in 2018 - but defeated Krunic 7-5, 6-4 in their only previous meeting, in the quarterfinals of the ITF $25,000 event in Kreuzlingen in 2014. The Serb, meanwhile, is on a five-match losing streak, having won just four games across her last three matches.

No.6 seed Caroline Garcia has one of the toughest first-round hurdles to clear as she takes on Johanna Konta in a battle of two former Top 5 players. The Briton leads the head-to-head 3-2, including their last encounter 7-6(3), 4-6, 6-4 in the fourth round of Wimbledon 2017, and also leads Garcia 2-1 on hard courts.



Click here for the full order of play for Day 2 at Flushing Meadows.


Indian Wells champion Naomi Osaka has been one of this year's sensations: "a global phenomenon as much for who she is on the court as who she is off it: quirky, honest and reserved," writes Shana Renee for Bleacher Report.

San Jose finalist Maria Sakkari is seeded at a major for the first time this week - and the "proud Spartan" sat down with Reem Abulleil for Sport 360 to discuss her partnership with coach Thomas Johansson and why she now has "a clear idea of what I have to do on court".

2017 semifinalist CoCo Vandeweghe is seeking to get a lean year back on track at the site of some of her greatest successes. The American talked to Vicki Hodges for the Telegraph about her love of team formats in an individual sport - and which sporting legend got her starstruck despite growing up in a family of them.