Naomi Osaka is the first Japanese major quarterfinalist since Shinobu Asagoe reached the last eight in New York in 2004, and is bidding to become the first Japanese major semifinalist since Kimiko Date at Wimbledon 1996. With Kei Nishikori also still alive in the men's draw, this year's US Open also marks the first time since Wimbledon 1995, when both Date and Shuzo Matsuoka were quarterfinalists, that a Japanese woman and a Japanese man have reached the last eight at the same Slam.
Lesia Tsurenko is aiming to be the first Ukrainian to reach a Grand Slam semifinal in history. Tsurenko is the third major quarterfinalist that the country has produced to date, following Kateryna Bondarenko and Elina Svitolina - of whom the former is the only Ukrainian to reach this stage at Flushing Meadows, back in 2009.
Naomi Osaka and Lesia Tsurenko have only met once before - in the semifinals of the Irapuato, Mexico ITF $25,000 event on hard courts in 2014. A 16-year-old Osaka won 6-4, 6-3, but would go on to lose the final to Indy De Vroome.
Australian Open quarterfinalist Carla Suárez Navarro has now reached the last eight of a Slam on seven occasions - but this is the first time that the 30-year-old has reached two major quarterfinals in the same season. Suárez Navarro is aiming to become the first Spaniard to reach the US Open semifinals since Conchita Martínez in 1996. The only Spaniards to have progressed to the quarterfinals in New York since then are Arantxa Sánchez Vicario (1997, 1998) and Suárez Navarro herself (2013).
Last year's runner-up Madison Keys sealed her first ever season with three Slam quarterfinal showings this week, and now the Roland Garros semifinalist will bid to make the final four of multiple Slams in one year for the first time. A win would also make the 23-year-old the youngest player with four major semifinals to her name (currently Garbiñe Muguruza).
Madison Keys leads the head-to-head 3-0 over Carla Suárez Navarro - but every match has gone to three sets. The American has won twice on hard courts - 5-7, 7-5, 6-2 in the first round of Tokyo in 2013 and 6-3, 3-6, 6-3 in the third round of the Rio de Janeiro Olympic Games in 2016 - and once on grass, 3-6, 6-3, 7-6(3) in the 2016 Birmingham semifinals.
At 20 years and 10 months old, Naomi Osaka is seeking to become the youngest US Open semifinalist since Caroline Wozniacki in 2010, who was 20 years and one month old. Osaka would also become the youngest active Grand Slam semifinalist with a win today, taking over from Jelena Ostapenko.
Lesia Tsurenko is guaranteed to hit a new career high ranking on Monday; her previous best was No.29, set in July 2017, but the 29-year-old will rise to at least World No.26 after her run in New York. Meanwhile, a win today would return Carla Suárez Navarro to the Top 20 for the first time since February 2017.
Madison Keys is one of only two players to have reached the quarterfinals or better at three out of the four majors in 2018, along with Angelique Kerber. If the American wins today, she will join Kerber, Simona Halep and Serena Williams as the only players to make the semifinals or better at two of the four Slams.
ORDER OF PLAY
Click here for today's full order of play at Flushing Meadows.
Anastasija Sevastova's clever, varied game has been an aesthete's delight for many years - especially at the US Open, where she backed up two previous quarterfinals to break through to her first major semifinal this week. In ending Sloane Stephens' title defence, the Latvian was the "weaver... of a captivating spider's web," writes Joel Drucker for tennis.com.
Serena Williams was giving birth this time last year, and has taken every match win of her comeback as a small step along the road to full form - but, now that the American is in her second consecutive major semifinal, "it's time to stop hedging predictions and start expecting Williams to win this tournament," argues Alyssa Roenigk for ESPN.com.