Jordan Lee finished a disappointing sixth in the T47 high jump at the World Para Athletics Championship in Dubai on Wednesday.
The 19-year-old Kerryman cleared 1.87m before failing three times at 1.91m.
Lee travelled to his first World Championships ranked number two behind eventual winner Roderick Townsend-Roberts.
The American jumped 2.03m to claim gold ahead Hongjie Chen of China in second and Nishad Kumar of India in third. The silver and bronze medallists both jumped 2.00m, 5cm higher than Lee's personal best of 1.95m set at the National Championships during the summer.
Lee's performance was not helped for a heel injury which he picked up in recent weeks.
"It was a funny old first experience," Lee said in an interview posted to the Paralympics Ireland YouTube channel.
"Unfortunately, it didn't go the way I planned it.
"I picked up an injury about a month ago that I kept low key. I injured my heel and it's been affecting me since. I was jumping through that and I was in a bit of pain today.
"At the end of the day, I can't make any excuses because when you start making excuses, I feel that's when an athlete is satisfied with where they're at. I'll never be satisfied with where I'm at.
"You interviewed me before at the Grand Prix in Paris where I jumped 1.92m and beat the European champion and Asian champion, I still wasn't happy with myself, so you can only imagine what I'm feeling like now.
"I'm going to bounce back from this. I believe that in these situations, it really shows and defines your true character, whether you can bounce back and rise above it. That's what I'm going to do.
"We're going to bounce back from this one and next year it will be a completely different story."