Angel Di Maria scored the only goal of the match as Argentina became CONMEBOL champions for the first time since 1993.
The match was evenly fought until a mistake from Renan Lodi allowed Di Maria to latch onto a beautiful cross from Rodrigo De Paul and fire home the opener.
Richarlison appeared to have restored parity for Brazil early in the second-half but was ruled out after the player was adjudged to have been offside in the build-up.
Neymar also came close soon after, but his shot was emphatically blocked by Emiliano Martinez as the Selecao piled on the pressure late on with the PSG star creating a lot of chances.
However, Lionel Scaloni's men weathered the late storm and were crowned Copa champions, as Lionel Messi finally got his hands on a major international title with Argentina.
Here are the hits and flops from the match:
Hit: Rodrigo De Paul (Argentina)
In a major final like this, you'd expect top stars like Lionel Messi, Angel Di Maria, Sergio Aguero, or even Alejandro Gomez, to come out as the best performers. Rodrigo De Paul, though, tore the script apart to emerge as Argentina's star of the match.
He absolutely bossed the midfield, combining technical excellence with athleticism to leave Brazil in knots, whilst also finding Di Maria with an exquisite cross over the top for arguably the best assist of the competition.
And it wasn't just the attack where he made an impression - De Paul tracked back when the Selecao pushed forward in search of an equalizer, closing down his side of the pitch to quell dangers, or jumping into tackles to impede their movements, completing all four of his attempts too.
Di Maria may have won the 'man of the match' award but De Paul was deserving of it too.
Flop: Fred (Brazil)
Going into the finals, Fred played every game for Brazil barring the dead rubber against Ecuador in their final group fixture, albeit to mixed results. The Manchester United star had only impressed in bits and parts - one assist in Peru thrashing a particular highlight - but produced another stinker today.
He went into the books as early as the third minute to catch Montiel with a late challenge and never recovered thereafter, struggling to gain possession and being outpaced by his Argentina counterparts.
Fred made one excellent tackle in the 18th minute when La Albiceleste looked to build attack with a series of passes, but that was the only bright moment in the 45 minutes he lasted, making zero interceptions, zero clearances, and winning zero duels during that period.
Hit: Angel Di Maria (Argentina)
It was a night of redemption for Angel Di Maria, who erased all the painful memories of the past with a match-winning goal for Argentina. The winger made the most of a mistake from Renan Lodi, who failed to clear the cross and took a sublime first-touch to lob the ball over Ederson.
That wasn't the only time the Argentina winger beat Lodi. The Atletico Madrid full-back was no match for his agility and struggled to keep him in check, while Di Maria also linked up well with Messi on a few occasions.
Few players can match his composure in a major final like this, having been a part of a few of them in the past. The man-of-the-match award was just the icing on the cake he spent the night baking.
Flop: Everton (Brazil)
The attacking flair with which Brazil tore sides asunder in this competition was sorely missing tonight, and part of the reason could be Everton's complete anonymity down the left flank.
With zero shots on target, zero shots off target, zero key passes and zero crosses, the Benfica forward was almost like a spectator. He also laid only 11 passes in 63 minutes of action, which begs the question - why didn't Tite replace him at half-time?
Sure, there was no Gabriel Jesus to call upon, but subbing on Everton Ribeiro would've at least guaranteed some urgency, with Roberto Firmino, a half-time substitute, also working hard to make something happen.
Hit: Neymar (Brazil)
Last but not least, a word of appreciation for Brazil's talisman, who gave his all today in another top-drawer performance against Argentina, only to see his dreams of lifting a first major international trophy with the Selecao, squished.
The prolific number 10 started as a centre-forward but dropped back to work his creative brilliance, conjuring chance after chance with spectacular throughballs and precise crosses.
Neymar also registered a mind-boggling 15 dribble attempts, completing nine, a testament to how big a threat he was for Argentina, who had no answer to his wizardry besides rough challenges.
Had it not been for Di Maria's winner, the man-of-the-match award would've surely gone to Neymar, whose sportsman spirit after the game was also admirable.