Ukraine 0-2 Argentina: Almada and Echeverri on target but Albiceleste forced to settle for second in Group B
Argentina were among the pre-tournament favourites to win a third gold medal, and their individual quality in the final third ultimately shone through in Lyon.
In a first half that saw just two shots on target, Argentina struck just two minutes after the break as Almada sent a curling effort beyond the grasp of Kiril Fesiun.
Ukraine threatened to snatch a point in the closing stages, but Echeverri secured the win in the first minute of injury time as he was quickest to react to Kevin Zenon's spilled effort.
But in the other game in Group B, Morocco swept aside Iraq as they emerged 3-0 victors, notching six points from their three games to top the group ahead of Javier Mascherano's side.
Argentina will face the winners of Group A in the last 16, which will be one of France, New Zealand or the United States.
Data Debrief: Argentina's individual quality the difference
Almada's stunning strike came with an expected goals (xG) of 0.03, once again showcasing his quality that has seen him shine for Atlanta United in the MLS this season.
Despite being the tournament's oldest player, Nicolas Otamendi showcased his experience at the back to help Argentina secure the victory.
The 36-year-old had the most touches (96), more accurate passes (85) and highest pass accuracy (97.7%) than anyone on the pitch.