A late rally away to Jaguares was not enough for the Blues to avoid suffering a third successive Super Rugby defeat.
A brace of tries from Ramiro Moyano helped power the Jaguares to a 23-19 victory at home to the Blues in Super Rugby on Saturday.
The visitors from New Zealand had led through Otere Black's early penalty in the second minute at the Estadio Jose Amalfitani, while Jaguares lost Thomas Lavanini to the sin-bin for a shoulder charge against Tom Robinson next to a ruck in the 31st minute.
Nevertheless, it was the hosts who went in 11-9 ahead at the half-time break in Buenos Aires, Moyano evading the attention of the defence to cross in the corner, although Joaquin Diaz Bonilla failed to convert.
Black sent over another penalty to regain the lead 10 minutes into the second half, but Moyano claimed his second try in the 64th minute, his pace again allowing him to pick a gap in the Blues' line and tear away to dot down close to the posts.
This time Diaz Bonilla managed to add the extras, and when a powerful maul towards the line resulted in a try for Julian Montoya in the 68th minute, the hosts were firmly in command, a review having indicated the hooker did not go into touch after breaking clear to score.
Dalton Papalii shrugged off a tackle and sprinted 20 metres to get one back for Blues, converted by Black with eight minutes to go, but the away side proved unable to build on their late rally.
A third successive defeat leaves Blues winless and fourth in the New Zealand Conference early in the campaign, while Argentina's lone representatives in the competition have now recorded two victories in three outings.