Coco Gauff ensured the watching American public had something to cheer at the US Open as she progressed to the fourth round on a day when Taylor Fritz, Amanda Anisimova and Madison Keys suffered shock defeats. Gauff, US Open champion in 2023, ground out a 6-3 6-4 win over world No 40 Cristina Bucsa and will next face Iva Jovic or Alexandra Eala.

Fritz, the ninth seed, blew a two-set lead against Federico Cerundolo, losing 3-6 4-6 6-3 6-4 6-4. Madison Keys collapsed after leading 5-0 in the deciding set against Zheng. Meanwhile, Ben Peterson, the 20th seed, faces Carlos Alcaraz in what should be a first genuine test of the defending champion's title credentials following his return from injury.

Elsewhere, Belgian 28th seed Alexander Blockx stunned Italian fifth seed Flavio Cobolli 6-7 (4-7) 6-3 6-0 6-3 to advance to the fourth round, where he will meet Argentina's 24th-seeded Cerundolo. The host nation is still looking for its first men's singles title winner since 2003, when Andy Roddick beat Juan Carlos Ferrero in the final.