Steve Finnan limped off on his debut for Portsmouth, who were crushed 4-0 by Benfica in their second and final match in the City of Guimaraes Trophy.
Oscar Cardoza's curling 16th-minute free-kick gave the Portuguese giants the lead and four minutes later the same player doubled the advantage when he rounded off a flowing move.
Finnan was introduced for the second half but within 25 minutes he went off injured with what appeared to be a hamstring injury and before substitute Luke Wilkinson could replace the former Liverpool defender, Benfica made it 3-0 when Weldon headed home Carlos Martin's cross.
And Benfica's emphatic victory was sealed with five minutes left when Wilkinson turned Di Maria's cross into his own net.