La Albiceleste will take on Venezuela on Thursday in the first round of knockout matches.
It took a huge gift from Bassam Hisham in the fourth minute for Argentina to fashion a lead. The Qatari defender inexplicably overlooked easier passing options from his position to the right of his goalkeeper in the 18-yard box and tried to smash an ambitious ball to the left flank. Martinez cut off the low pass with ease and slid the ball beyond Saad Al Sheeb with his second touch.
Argentina constructed its own chances thereafter, with Manchester City pair Aguero and Nicolas Otamendi guilty of wasting clear opportunities. But, even though there were clear improvements from La Albiceleste in the weekend affair, Lionel Scaloni's team was sometimes disjointed in midfield and susceptible at the back.
Aguero continued to be lively in the second half and forced good saves from Al Sheeb on a few occasions, eventually getting his reward after 82 minutes. It was worth the wait: the 31-year-old showed a great turn of pace as he skipped one challenge and surged past Boualem Khoukhi before side-footing into the far bottom corner.