Otto travelled to Estonia to play his second Tennis Europe 12U event, alongside fellow Great Briton, Jack Draper.
The international field contained representatives from eight nations, including the top ranked players from Finland, Poland and Estonia.
Otto gained valuable playing experience on the less than familiar European red clay. Despite his relative inexperience on the surface to his European counterparts, he won through to the semi finals of the singles, beating the Estonian number one along the way.
Representing Great Britain with partner Jack Draper, Otto reached the Boys Doubles final, losing a tense encounter 2-6, 6-4, 0-1(6) to the top Finnish pair.
Otto is one of the Lincolnshire 12U boys attending a pre-selection training session on 15 June in preparation for the 12U Boys County Cup event 29 and 30 June at Northampton.
Report supplied by Jason Revill, Otto's coach