US Open ATP Day Nine Round-Up | Alexander Zverev keeps rolling as Khachanov stages huge comeback against Tien

The US Open men's draw produced another day of dramatic battles, with Alexander Zverev advancing in straight sets while Alexander Blockx continued his stunning run by eliminating Francisco Cerundolo. Karen Khachanov also came back from a set down to defeat Learner Tien in five sets, while Botic van de Zandschulp completed another comeback against Arthur Gea in a marathon clash.

Zverev's dominant win contrasted sharply with three matches that went deep, as Blockx held his nerve against Cerundolo and Khachanov overturned a deficit against Tien. Van de Zandschulp also recovered from two sets down to keep his remarkable New York run alive, setting up another intriguing chapter in the men's quarterfinal picture.

Alexander Blockx continued his remarkable US Open run by overcoming Francisco Cerundolo in four sets to reach his first Grand Slam quarterfinal. The Belgian was forced to respond after dropping the opening set, but gradually found a way to make the match increasingly uncomfortable for the 24th seed, particularly in the longer exchanges.

Cerundolo had chances to regain control, especially in the third set, but Blockx repeatedly held his nerve at the most important moments. The Belgian saved three break points while serving at 5-5 before immediately putting pressure on Cerundolo and taking the set. He then carried that momentum into the fourth, breaking late to close out another impressive victory.

After already defeating fifth seed Flavio Cobolli in the previous round, Blockx has now added another seeded player to his run in New York. The 21-year-old will head into the quarterfinals with his confidence soaring after another performance in which he refused to let a difficult start derail him.

Karen Khachanov produced one of the biggest fightbacks of the day as he recovered from a set and a break deficit to defeat 14th seed Learner Tien in a five-set battle. The Russian had already taken the opening set 7-5, but Tien responded impressively, taking the second 6-4 before edging an extremely tight third-set tiebreak 8-6 to move within one set of the quarterfinals.

That was when the match changed completely. With Tien seemingly in control, Khachanov raised his level and began dictating the rallies more consistently, taking advantage of the American's drop in intensity. He raced through the fourth set 6-1, immediately putting Tien under pressure and forcing the match into a deciding set.

The fifth set remained competitive, but Khachanov had already shifted the momentum firmly in his favor. He stayed composed through the closing stages and eventually completed the turnaround 6-4, ending Tien's run in New York. For the Russian, who reached the US Open semifinals in 2022, it was a particularly impressive response after appearing to be on the brink of elimination following the third-set tiebreak.

Botic van de Zandschulp completed another extraordinary comeback to reach the US Open quarterfinals, overcoming Arthur Gea after nearly four hours of tennis. The Dutchman appeared to be heading out when Gea took control early, winning the opening set 6-3 and then edging a tight second-set tiebreak to move within one set of a place in the last eight.

Van de Zandschulp, however, refused to let the match slip away. He managed to force the contest into a fourth set and then survived another tense tiebreak, setting up a deciding fifth after Gea had twice moved within one set of victory. With both players having spent significant time on court throughout the tournament, the final set became a test of composure as much as tennis.

Van de Zandschulp handled that test better. After four sets decided by increasingly fine margins, the Dutchman finally created the separation he had been looking for in the fifth, closing out the 6-4 set to complete the comeback. It marks another significant win for the 30-year-old, who had already knocked out sixth seed Alex de Minaur in straight sets before surviving Zizou Bergs in five sets in the previous round.

Gea's defeat nevertheless brings an extraordinary run to an end. The 21-year-old entered the main draw as a lucky loser after Casper Ruud withdrew and arrived in New York having won his first ATP title in Los Cabos only weeks earlier. He leaves the tournament after reaching the second week of a Grand Slam for the first time.

Alexander Zverev produced another convincing performance as he swept aside Luciano Darderi in straight sets to reach the US Open quarterfinals. The German immediately established control from the baseline, using his serve to set up the first strike and repeatedly forcing Darderi into defensive positions. He broke early in both opening sets and never allowed the Italian to build any sustained momentum, taking them both 6-2.

Zverev's serve was a major factor throughout the match. He landed 72% of his first serves, comfortably ahead of Darderi's 48%, and won 86% of the points behind that first delivery. That combination made it extremely difficult for Darderi to put pressure on the German's service games. The Italian earned only one break-point opportunity all match, which Zverev saved, while the top seed kept knocking on the door at the other end, converting four of 17 break chances.

Darderi finally managed to make the contest more competitive in the third set, staying with Zverev for longer in the rallies and forcing a tiebreak. But even then, the German's greater weight of shot continued to show. Zverev finished with 43 winners to Darderi's 30, and when the set reached its decisive stage, he stayed composed to close out the tiebreak 7-5. After two comfortable sets, he had to work harder for the finish, but ultimately completed another controlled performance without allowing the match to become a five-set battle.