The win placed Lionel Messi's La Albiceleste top of Group A with seven points -- enough to secure its spot in the next phase of the tournament being played in empty stadiums in coronavirus-battered Brazil.
The match marked a personal milestone for Messi, who tied Javier Mascherano's record for the most games played for Argentina -- 147.
But it was not a night of glory for Messi or his team, who in the second half seemed to resign themselves to defending a spirited, but ultimately fruitless, Paraguayan attack.
In the other match Monday, Chile drew 1-1 with Uruguay to end the day with five log points.
With four matches left to play in Group A, Paraguay has three points, Uruguay one, and Bolivia zero, meaning they all still stand a theoretical chance to go to the quarter-finals.
Brazil has already qualified from Group B.