Aryna Sabalenka continued her US Open title defense with a straight-sets victory over Taylor Townsend, while Linda Noskova survived a dramatic three-set battle against 11th seed Marta Kostyuk to book her place in the quarterfinals. Jessica Pegula also advanced after overcoming a determined Sorana Cirstea in straight sets.

The results set up an intriguing quarterfinal between Sabalenka and Noskova, with the world No. 1 still unbeaten in New York and the Wimbledon champion continuing her impressive run. Pegula, meanwhile, moved one step closer to another deep run at the US Open as she continues her bid for a maiden Grand Slam title.

Sabalenka advanced without dropping a set, although the world No. 1 was not at her sharpest on serve. She won just 31% of points behind her second serve and was broken four times, but compensated by constantly putting pressure on Townsend's delivery and breaking the American seven times.

The opening set was particularly chaotic, with seven of the first eight games ending in breaks. The only hold came when Sabalenka held in the sixth game to move ahead, but Townsend refused to let her opponent pull away. After falling behind 2-5, the American won two games in a row and even earned a break point to level the set at 5-5. Sabalenka held firm, however, and closed out the opening set on her own serve.

The second set initially followed a more conventional pattern, with both players improving their serving. Townsend nevertheless found another opening and moved 3-1 ahead, but Sabalenka responded immediately. The top seed took control of the final stages, winning five consecutive games to complete the victory and set up a quarterfinal against Noskova.

Noskova survived a fiercely contested battle with 11th seed Kostyuk to reach the US Open quarterfinals for the first time. The sixth seed used her reliable backhand to disrupt Kostyuk's serve in the opening set, while her forehand provided several important winners as she secured the decisive break in the 11th game before serving out the set.

Kostyuk appeared to be in serious trouble again in the second set when two double faults and an unforced error handed Noskova a break in the seventh game. However, the Ukrainian refused to go away. She fought back late in the set and broke Noskova to love in the 12th game to force a decider.

Noskova recovered her composure in the final set and moved ahead 4-3 after producing another superb backhand winner. Kostyuk struggled to contain her frustration as the pressure mounted, and Noskova eventually closed out the victory 6-4. She now faces defending champion Sabalenka in one of the standout quarterfinals.

Pegula had to work much harder than the scoreline suggests to overcome the ever-competitive Cirstea. The third seed made a flying start, winning the first 13 points of the match and taking two consecutive breaks to move 3-0 ahead. It took Cirstea a few games to settle, but once the Romanian found her range from the baseline, she began putting consistent pressure on Pegula.

Pegula remained composed and trusted her game in the New York conditions, earning another break to move 5-2 ahead. She was unable to serve out the set immediately, however, as Cirstea fought back and forced her to save several opportunities before Pegula finally converted her sixth set point from the return to take the opening set.

The second set became another momentum battle. Pegula again opened a lead, moving 4-1 ahead, but Cirstea refused to surrender. The final games featured a series of break opportunities on both sides, with four of the last five games going against serve. Pegula eventually held her nerve and converted her third match point to complete the victory and move into the quarterfinals.

Anna Kalinskaya 4-6, 2-6 Emma Navarro

Navarro booked her place in the US Open quarterfinals with a convincing straight-sets victory over Kalinskaya, gradually taking control of a match that was much tighter than the final scoreline suggested. The opening set was particularly competitive, with both players protecting their serves comfortably through the first eight games and neither able to create a break-point opportunity. Navarro stayed patient during the extended baseline exchanges, refusing to force the issue as Kalinskaya matched her from the back of the court.

That balance finally shifted at the most important moment of the opening set. At 4-4, Navarro continued to apply pressure and eventually created her first break point of the match, immediately converting the opportunity to move ahead. She then held her nerve on serve to close out the set 6-4, turning a previously even contest into one where she had the momentum. Kalinskaya was unable to find an immediate response at the start of the second, while Navarro looked increasingly comfortable dictating the direction of the rallies.

The American then made the decisive move at 1-1, breaking Kalinskaya to take control of the set. She backed it up with another hold and never allowed her opponent to build any sustained pressure, eventually moving 5-2 ahead before closing out the match 6-2. Navarro's ability to stay composed during the tight opening stages and then capitalize when opportunities appeared proved decisive, and she will now face fellow American Jessica Pegula in the quarterfinals.