Wales narrowly lost to Argentina in the cup quarter-final of the International Rugby Board Dubai Sevens in Dubai.
A converted try was all that separated Paul John's side in the 7-5 defeat, with Alex Walker missing his kick after Owen B Williams crossed the line.
Antonio Ahualli de Chazal's second half try was then converted by Joaquin Diaz Bonilla to give Argentina the win.
Wales again tasted defeat later on day three when John's side lost 22-7 to South Africa in the plate semi-final.
Wales had previously dominated Pool D on day one of the competition, beating Australia 33-14 in their final game.
John's side had narrowly beat Canada 15-12 with a late Ifan Evans try before beating Scotland 14-7 with Tom Prydie and Will Price going over, the latter in the dying moments.
Richard Smith (2), Tom Habberfield, Owen Williams and Evans went over against Australia.
Wales won the plate in the world series opening tournament on the Gold Coast in November, losing to Fiji in the last eight on the way.