The Fiji Airways Men's National 7s side finished in fourth place at the Valladolid 7s in Spain, following their 28-17 loss to Argentina.
The Los Pumas capitalise on Fiji's mistakes and use the width of the field to stretch the defence.
Fiji started well with a try to Apete Narogo in the first few seconds of the first half to put them in a 7-0 lead.
Argentina responded a minute later through Marcos Moneta, who levelled the score at 7-all.
They scored another two tries to Luciano Gonzalez and Pedro De Haro to put them in a 21-7 lead.
Fiji's Isaia Rugu crossed over the tryline in the sixth minute to close the gap to a 12-21.
Argentina led Fiji 21-12 at halftime.
The second half saw both teams score a try each, with Jeremaia Matana scoring for Fiji, while Moneta scored his second and sealed the Pumas' win.
In other results, Uruguay beat Great Britain 19-17 in the 11th-place playoff, the USA defeated Germany 28-21 in the 9th-place playoff, France beat Kenya 14-5 in the 7th-place playoff, and New Zealand beat Spain 22-12 in the 5th-place playoff.
Meanwhile, Australia will face South Africa at 2.26am today in the cup final.
Updates
Kick off: Argentina
0'Try to Fiji. Apete Narogo. FJ 7-0 ARG
2' Try to Argentina. Marcos Moneta. FJ 7-7 ARG
3' Try to Argentina. Luciano Gonzalez. FJ 7-14 ARG
5' Try to Argentina. Pedro De Haro. FJ 7-21 ARG
6' Try to Fiji. Isaia Rugu. FJ 12-21 ARG
HT: FJ 12-21 ARG
2ND HALF.
Kick off: Fiji
9' Try to Fiji. Jeremaia Matana. FJ 17-21 ARG
11' Try to Argentina. Marcos Moneta. FJ 17-28 ARG
