The Round of 16 at Flushing Meadows promises fireworks on Labor Day Monday, with the bottom half of the women's draw serving up a tantalizing mix of Grand Slam champions, rising stars, and potential upsets. The spotlight shines brightest on the Arthur Ashe Stadium showdown between defending champion Coco Gauff and two-time US Open winner Naomi Osaka, a match that carries both history and high stakes. Meanwhile, world No. 2 Iga Swiatek faces a surging Ekaterina Alexandrova, and the in-form Amanda Anisimova continues her impressive summer against Beatriz Haddad Maia, who plays her best tournament since plenty of months.
Gauff vs. Osaka
The 21-year-old Gauff enters this marquee matchup with renewed confidence after dismantling Magdalena Frech 6-3, 6-1 in just 66 minutes on Saturday. The American's serve, which had been a source of concern earlier in the tournament, showed marked improvement with a 71% first-serve percentage and only four double faults across the entire match. After suffering what she described as a "panic attack" during her emotional second-round victory over Donna Vekic, Gauff has steadied the ship remarkably. The 76.1% was her best first serve accuracy recorded since April's quarterfinal match in Stuttgart, while facing just two breakpoints was her most calm day on serve also since April, when she faced no single breakpoint against Iga Swiatek in semifinals of WTA 1000 in Madrid.
Osaka's resurgence at Flushing Meadows has been nothing short of spectacular. The 23rd seed demolished Daria Kasatkina 6-0, 4-6, 6-3 in the third round, delivering her first bagel set at a major since the 2022 Australian Open. This marks the Japanese star's first appearance in the second week of a Grand Slam since her 2021 Australian Open triumph, and her 26th US Open match win ties this tournament with Melbourne as her most successful major venue. Under the guidance of new coach Tomasz Wiktorowski, Osaka has won 10 of her last 13 matches, showcasing the controlled aggression that carried her to four major titles. She blasted 37 winners against Kasatkina while maintaining impressive court coverage. The lost of focus after winning first set in a smashing way did not discourage Osaka as well, as she came back deliver when it was needed in third set, firing 15 winners in the decisive set.
Their head-to-head stands at 3-2 in Gauff's favor, but their most memorable encounter remains their 2019 US Open third-round meeting when Osaka, then the defending champion, defeated a 15-year-old Gauff before consoling the tearful teenager in an iconic moment of sportsmanship. Five years later, the power dynamic has shifted dramatically. Gauff has won three of their four meetings since that night, but the latest one in China Open 2024 ended up with Osaka's withdraw before the start of third set.
Swiatek vs. Alexandrova
Swiatek's quest for a second US Open title faces a stern test against the red-hot Alexandrova. The Polish star endured a dramatic third-round encounter with Anna Kalinskaya, recovering from 1-5 down in the opening set to prevail 7-6(2), 6-4 in nearly two hours on Arthur Ashe Stadium. Kalinskaya appeared poised to claim the first set after racing to a 5-1 lead, holding four set points at 5-2, but Swiatek mounted a stunning comeback, winning six of the next seven games and dominating the tiebreak 7-2. The second set saw both players trading early breaks before Swiatek seized control with a crucial break in the ninth game, closing out the match when Kalinskaya yanked a return wide. Earlier in the tournament, Swiatek had survived a little scare against Suzan Lamens, dropping a set before prevailing 6-1, 4-6, 6-4.
Alexandrova arrives at this fourth-round showdown in devastating form after obliterating Laura Siegemund 6-0, 6-1 in exactly 60 minutes, one of the most lopsided third-round victories in recent US Open history. The 13th seed has demonstrating the kind of aggressive baseline tennis that has carried her to a career-high ranking of No. 12. The Russian has now reached the fourth round or better at three consecutive majors, winning 77% of her return games throughout the tournament - the highest percentage of any remaining player. Winning 100% of second return points against Siegemund is also the very unique and remarkable stat to achieve.
The head-to-head favors Swiatek 4-2, with the Pole winning their most recent encounter 6-4, 7-6 in the Bad Homburg quarterfinals in June. However, Alexandrova holds a 2-1 advantage on hard courts, including a memorable 6-4, 6-2 victory Miami last year. The Russian's flat, penetrating groundstrokes and improved return game could pose problems for Swiatek, who has shown vulnerability when opponents successfully neutralize her heavy topspin and dictate rallies from inside the baseline. The Russian is surely the player who can exploit the vulnerabilities already displayed by Swiatek in this tournament in more effective way than previous opponents of the Pole.
Anisimova vs. Haddad Maia
The eighth-seeded Anisimova continues her career-best season after grinding past Jaqueline Cristian 6-4, 4-6, 6-2 in a third-round battle that tested her resilience. The American, celebrating her 24th birthday on the eve of this match, has compiled 11 major wins in 2025 - matching her 2022 total - and arrives fresh off her runner-up finish at Wimbledon. Despite a 5-7 record since that breakthrough run at the All England Club, Anisimova's aggressive baseline game remains intact, as evidenced by her dominant first two sets against Cristian before the Romanian mounted a spirited comeback.
Haddad Maia demolished Maria Sakkari 6-1, 6-2 in her third-round match, extending her perfect 4-0 record against the Greek player. The 18th seed needed just over an hour to dispatch Sakkari, breaking serve seven times and winning 77% of points on Sakkari's second serve. This victory trademarks the comeback on rails for the Brazilian who struggles with an abysmal season up to this point - she entered US Open with just 10 wins and 23 losses in 2025. The potential victory over Anisimova could replicate last year's quarterfinal run and deny the drop of many points, slowing down the imminent falldown in rankings.
This marks their third career meeting, with Haddad Maia winning their last encounter on hard courts by 6-4 7-5 in Adelaide, January 2023. The stylistic contrast should produce compelling tennis - Anisimova's flat, powerful groundstrokes against Haddad Maia's heavy topspin and superior defensive skills. The American is the obvious favorite comparing the performance of both this season, however Haddad Maia has already shown the excellence in making deep runs in Grand Slams in the past. Both are proven to deliver on that stage, so it can be an interesting encounter, with the home representative being a pre-match favorite.
Muchova vs. Kostyuk
The 11th-seeded Karolina Muchova showcased her renowned fighting spirit by recovering from a set down to defeat Linda Noskova 6-7(5), 6-4, 6-2 in an all-Czech battle. After squandering a 5-3 first-set lead and a set point, Muchova regrouped impressively, breaking late in the second set before dominating the decider. The former world No. 8 continues her impressive record at Flushing Meadows, having reached the semifinals in both 2023 and 2024. Her all-court game, featuring exceptional variety and court craft, has carried her through three demanding matches, including a three-set opening victory over Venus Williams.
Marta Kostyuk demonstrated her resilience in overcoming Diane Parry 3-6, 6-4, 6-2, converting crucial break points in the final two sets after dropping the opener. The 27th seed was a superior force on the court, producing 48 pressure points while facing 26 on own serve, however she was very inconsistent with translating that into score. She needed 16 breakpoints to convert just 5 out of those. The Ukrainian's powerful baseline game and improved consistency have yielded her best US Open result, matching her third-round appearance from 2020. She won 31 of 47 points in the decisive third set, overwhelming Parry with aggressive returns and penetrating groundstrokes.
This will be the first career meeting between Muchova and Kostyuk, presenting an intriguing clash of styles. Muchova's variety and tactical acumen against Kostyuk's raw power and improving consistency promises to deliver high-quality tennis. The Czech's experience in the latter stages of majors could prove crucial, having reached at least the quarterfinals in four of her last seven Grand Slam appearances when healthy. However, Kostyuk's hunger for a breakthrough result and her powerful game suited to the US Open's fast courts make her a dangerous opponent.
