 In 2004, he moved to the top level with Asunción's Club Nacional, where he quickly established himself as the team's top scorer, scoring 17 overall goals in his last season.Cardozo arrived at Argentina and Newell's Old Boys in the second half of the 2006–07 season for a transfer fee of $1.2 million, joining compatriots Diego Gavilán, Santiago Salcedo and Justo Villar.He netted 11 goals in only 16 games in the "Apertura", but his team could only finish 18th in the tournament, and 13th overall.