Sergio Aguero ended his long wait for an Argentina goal in his first start under Jorge Sampaoli as the South American giants left it late to beat Russia 1-0 at the Luzhniki Stadium.
Aguero found the net for his country for the first time since June 2016 in the 86th minute on Saturday, continuing the form that saw him become Manchester City's all-time leading goalscorer this month.
The 29-year-old, benefitting from Mauro Icardi's withdrawal from the squad due to injury, proved Argentina's most dangerous player and was twice denied by impressive saves from Russia goalkeeper Igor Akinfeev.
Aguero fed star Lionel Messi for an opening that was thwarted by a goal-line clearance early in the second half, while Denis Glushakov went close with a pair of rare opportunities for the hosts of next year's World Cup.
The breakthrough finally came when Aguero headed home with four minutes remaining, though there will remain concerns about Argentina's difficulties in breaking down a resilient Russia side, who were playing at the Luzhniki for the first time since its redevelopment.
Stanislav Cherchesov's side made it difficult for Argentina, who handed debuts to Giovani Lo Celso and German Pezzella from the start, by pressing high in the opening stages, with Messi unable to get on the end of a bright exchange with Eduardo Salvio following a surge down the right.
The first real opening came when Angel Di Maria's cross-goal shot from Messi's lay-off was kept out by Akinfeev, and Aguero was unable to turn home the loose ball from an acute angle.
Akinfeev produced an impressive one-handed stop to keep Aguero's low effort from 20 yards out of the bottom-right corner midway through the half.
Sampaoli's side dominated possession but were unable to break through, another excellent stop from Akinfeev low to his right denying Aguero on the stroke of half-time.
Messi almost opened the scoring within three minutes of the restart but his chip over Akinfeev after a lovely throughball from Aguero was cleared by Konstantin Rausch with Salvio lurking behind.
Glushakov arrowed an effort wide and saw a thumping strike after a scramble in the box blocked by Sergio Romero, the goalkeeper making his first save just before the hour mark.
Nicolas Otamendi's overhead kick was pushed over the top by Akinfeev and Di Maria shot wide in the 68th minute, with the visitors unable to make their dominance in possession count.
Diego Perotti made his first Argentina appearance in over six years and Cristian Pavon was handed a first cap as Sampaoli sought a winner.
And, after Romero backpedalled to stop Rausch scoring directly from, Boca Juniors forward Pavon played a role in the winner.
He latched onto Messi's pass and found Aguero with a cut-back from the right side of the box. Giorgi Jikia blocked the City striker's initial effort but his follow-up header denied Russia a creditable draw in front of their own fans.
Cherchesov's men will continue their World Cup preparations against Spain in St Petersburg on Tuesday, while Argentina travel to Krasnodar to take on Nigeria on the same day.
