Defending US Open women's singles champion Coco Gauff followed Novak Djokovic out of Flushing Meadows with a shock fourth-round exit to compatriot Emma Navarro.
The 20-year-old has always been renowned for her struggles on serve during the embryonic stages of her career, which she has been working tirelessly to improve, but Sunday's match was double faults galore for the defending champion.
Navarro capitalised on a staggering 19 double faults from Gauff to triumph 6-3 4-6 6-3 against her fellow American in two hours and 12 minutes, thereby reaching the US Open quarter-finals for the first time in her own fledgling career.
The duo came into Sunday's fourth-round tie having trodden similar paths, with Gauff easing past Varvara Gracheva and Tatjana Maria in her opening two ties while Navarro made light work of Anna Blinkova and Arantxa Rus.
Both women were coincidentally taken to three sets by Ukrainian opponents in the third round - Elina Svitolina for Gauff and Marta Kostyuk for Navarro - but it was chalk and cheese as far as serving went at the Arthur Ashe Stadium.
Indeed, Gauff's 19 double faults were the joint-most she had ever served in a single match, level with the 19 she posted during a French Open clash against Martina Trevisan four years ago, while Navarro only committed two such mistakes.
Despite her perpetual problems behind her own racquet, Gauff enjoyed a mini-resurgence at the end of the second set to level the match, only to continue to commit fatal mistakes as the third wore on.
As well as her 19 double faults - which was five more winners than she managed - the defending champion committed an unsightly 60 unforced errors, including on match point, where she horribly overcooked a forehand.
Navarro's beating of Gauff saw lightning strike twice for the 23-year-old, who also overcame her countrywoman in the last 16 of Wimbledon, and she will take on Paula Badosa for a spot in the semi-finals.
Who is playing at the US Open on Monday?
Gauff's fourth-round exit and Djokovic's third-round loss means that there will be a new king and queen of New York later this month, and the fourth-round action continues on Monday with the top seeds.
Jannik Sinner and Iga Swiatek headline the evening session at Arthur Ashe Stadium, facing Liudmila Samsonova and Tommy Paul respectively, while Jack Draper - the last Briton standing - bids for a quarter-final place too.
The national number one returns on the back of defeating Carlos Alcaraz's conqueror Botic van de Zandschulp, and the Czech Republic's Tomas Machac now stands in his way. body check tags ::
