Jack Draper never considered retiring in his straight-sets semifinal defeat to top seed Jannik Sinner on Friday, the Briton said, after a gruelling match that saw him vomit three times.
The 25th seed had not dropped a set in New York before Friday but his dream run to a first major semifinal quickly turned into a nightmare as heat, humidity and nerves saw him queasy by the second set.
The 22-year-old said it only got worse from there, as he became dizzy because he was unable to take in much fluid. He lost 7-5 7-6(3) 6-2.
"I'm not going to retire in the semis of a Grand Slam. I know the last set, you know, it probably looked liked from courtside or on TV that it was, you know, not a great look," he said.
"I was fighting hard. You know, I'm proud of myself. I tried to fight as hard as I can. Just not going to get it done against someone like that."
There were plenty of positives for Draper to take from his 10th major main draw, as he became the first British man to reach the U.S. Open semifinals since Andy Murray won the tournament 12 years ago.
Draper was ranked 123rd when he made an inspired run to the fourth round last year despite an injury-plagued season, and he believes he will get results with more experience.
"I just need to keep on learning, keep on growing, keep on having situations like today where I came unstuck," he said.
"It's experiences, doing all the right things, it's training consistently, and over time you just progress and you get stronger and you get better."