Britain's Alfie Hewett was beaten by Stephane Houdet in the final of the wheelchair singles at the US Open.
The 19-year-old from Norfolk had hoped to add the title in New York to the maiden grand slam trophy he won at the French Open earlier this summer.
But Hewett succumbed to fatigue and the experience of 46-year-old Frenchman Houdet, losing 6-2 4-6 6-3.
It has been a busy couple of days for Hewett, who edged compatriot Gordon Reid in a three-hour semi-final on Saturday before teaming up with the Scot to beat Houdet and Nicolas Peifer in the doubles final.
The teenager was out-manoeuvred by Houdet in the opening set and could not hide his frustration in the final game but he recovered from a break down in the second to level when the Frenchman double-faulted.
However it was Houdet, for whom this is a first slam singles title in four years, who was the stronger in the final set, Hewett failing to hold his serve once.
Hewett said: " Congratulations to Steph for a great final. I just didn't have enough in the tank today after such an exhausting singles and doubles yesterday.
"But I'm proud to be in the final, my first time here, there's a lot of positives to take and hopefully I can be back next year."