US Open WTA Day Six Round-Up | Sabalenka and Pegula advance as Cîrstea and Navarro score statement wins

Day six brought contrasting fortunes for several of the women's contenders, with Aryna Sabalenka and Jessica Pegula overcoming different kinds of tests to reach the fourth round. Sabalenka produced another aggressive straight-sets victory against Kamilla Rakhimova, while Pegula recovered from a slow start to defeat fellow US Open finalist Leylah Fernandez in three sets.

There was also a pair of statement wins further down the draw. Sorana Cîrstea knocked out two-time Grand Slam finalist Jasmine Paolini in straight sets, while Emma Navarro produced one of the day's biggest results by sending Karolína Muchová out. Marta Kostyuk continued her excellent Grand Slam form with another convincing victory, setting up a fourth-round meeting with Linda Noskova.

Sabalenka continued her march through the US Open with another straight-sets victory, needing around an hour and a half to overcome Rakhimova. The world No. 1 was particularly impressive behind her serve, winning 76% of points behind her first delivery and 73% behind her second while never allowing the Russian to earn a single break point. That gave Sabalenka the freedom to attack aggressively from the baseline, and she finished with 29 winners to Rakhimova's 14.

The first set was effectively decided by Sabalenka's fast start. She secured an early break and backed it up with strong serving to move 3-0 ahead before protecting the advantage for the remainder of the set. Rakhimova struggled to find a response to the pressure, while Sabalenka converted two of her seven break opportunities overall.

The second set was more competitive, with Rakhimova repeatedly saving break points and navigating several deuce games to keep herself in front. When the Russian moved ahead 4-3, however, Sabalenka remained composed and raised her level at the decisive moment. She won the final three games in a row to close out the 6-3, 6-4 victory and book a fourth-round meeting with Taylor Townsend.

Cîrstea produced one of the day's standout performances by eliminating two-time Grand Slam finalist Paolini in straight sets. The Romanian recovered from an early break in the opening set and quickly turned the momentum around, winning two consecutive return games to establish control. She was also far more effective behind her serve, winning up to 67% of her service points compared with just 43% for Paolini.

The second set followed a similar pattern. Paolini again made the better start and moved ahead after an early break, but Cîrstea refused to let the advantage last. The turning point came during a lengthy game in which she missed five break opportunities before finally converting the sixth to level the set at 3-3.

From there, Cîrstea completely took over. The veteran Romanian won six games in a row, closing the match with authority as Paolini struggled to regain the level she had shown at the start. Cîrstea's ability to absorb Paolini's early pressure and then become increasingly aggressive from the return proved decisive as she secured one of the biggest wins of her tournament.

Kostyuk continued her remarkable Grand Slam consistency with another commanding performance against Alexandrova. The Ukrainian now has 16 wins in her last 18 Grand Slam main-draw appearances, having reached consecutive semifinals at Roland Garros and Wimbledon earlier this season. On both occasions, her run ended against a fellow rising star in Mirra Andreeva and Noskova respectively, but she once again looks capable of making another deep run in New York.

Kostyuk established control early in the opening set, creating a double-break advantage before serving it out 6-3. Alexandrova found a way to disrupt her rhythm at the beginning of the second, breaking first to move ahead, but Kostyuk responded immediately and then went on a six-game winning streak that effectively decided the match.

After just 78 minutes, Kostyuk completed the 6-3, 6-2 victory and moved into the fourth round. Her next opponent will be Noskova, setting up a rematch of their Wimbledon semifinal from two months ago.

Pegula had to recover from a disastrous opening set to defeat Fernandez in a clash between two former US Open finalists. The Canadian, who reached the final in 2021, immediately broke and took advantage of an erratic start from Pegula. The American landed just 31% of her first serves in the opening set and failed to create a single break opportunity, while Fernandez converted both of the chances she earned.

The match changed significantly in the second set. Pegula cleaned up her serving and became much more precise from the baseline, increasing her winner count from just three in the first set to 13 in the second. She broke early and built a 5-2 advantage, only for Fernandez to immediately break when Pegula attempted to serve for the set.

The American did not let the setback derail her. With Fernandez serving at 5-4, Pegula found the return she needed to break straight back and force a deciding set. She again secured the first break in the third and, after moving ahead 3-1, neither player created another break opportunity. Pegula protected her advantage with her serve and completed the comeback to reach the fourth round.

Navarro produced another major result at Flushing Meadows by eliminating Muchová in straight sets. The Czech entered the contest as the favorite, but Navarro consistently exposed weaknesses in her opponent's service games, particularly when attacking the second serve. Muchová landed only 53% of her first serves and won just 21% of her second-serve points, leaving Navarro with repeated opportunities to apply pressure from the return.

The American made the most of those openings in the first set, winning three consecutive games from 3-3 to take control. Muchová responded better in the second, and the two players traded breaks twice in a row as neither could establish a sustained advantage.

The decisive moment came late in the set. Navarro found a break when it mattered most and then closed out the match after winning three consecutive games to turn a tight contest into a straight-sets victory. She finished with 16 winners to Muchová's 18, but the difference in consistency was significant: Navarro committed just 18 unforced errors compared with 32 from the Czech, allowing her to stay in rallies and capitalize when the match reached its defining moments.