Goals from Sergio Aguero and Lionel Messi – the second from the penalty spot – scarcely did justice to the Argentines’ first-half dominance, but a Nelson Valdez cracker (60) gave Paraguay a lifeline.
And it was Argentina-born substitute Lucas Barrios who lashed in an equaliser in the last of the 90 minutes to leave Uruguay – winners against Jamaica earlier – top of Group B.
It was an outcome that did not seem likely when Miguel Samudio’s blind back-pass allowed Aguero to sidestep Antony Silva and slot the opening goal (29).
The hapless Samudio then ploughed into Angel Di Maria to give Argentina a penalty, which Messi buried to put his side in total control.
Paraguay escaped on two fronts at the start of the second half – substitute Derlis Gonzalez avoiding a second yellow card in short order for a poor tackle on Di Maria and Silva stopping Messi with his legs.
And Valdez blasted them back in the game from 20 yards moments after Sergio Romero’s one-handed stop had denied him.
The last half-hour was a free-for-all, Valdez flicking off target at one end and Messi firing across the face of goal at the other.
Both ‘keepers kept the score at 2-1, Silva reacting sharply to beat out Javier Pastore’s close-range drive before Romero’s reflexes denied Samudio a redemptive equaliser.
But just as it seemed Argentina had weathered the storm a deep free-kick was knocked down to the edge of the box for Barrios to blast inside the near post.