Piper claimed victory in the under-14 boys’ double mini trampoline competition in the city of Santarém.
He topped the qualifying round with 64.800 points and then scored 65.900 points in the final to take the title ahead of Spain’s Luis Sanchez and Javier Martinez. They were the only three divers to score more than 60.000 points in the final.
Piper had previously won a team and a synchro gold for Great Britain but this was his first individual title representing his country at an international competition.
It will have boosted his chances of earning selection for December’s World Age Group Championships in Tokyo. Great Britain will name their squad for that this month.