World Football - Argentina book place in quarters
All three goals were penalties on a day when spot kicks settled each of the four matches played.
Erik Lamela netted two for Argentina while Mohamed Salah's effort from 12 yards kept the score close and set up a nervy finish for the Albiceleste.
Argentina have now gone 17 games unbeaten at the competition, a run stretching from their opening defeat to the USA in the 2005 edition.
They now face Portugal in the quarter-finals after the European side beat Guatemala 1-0, thanks to Nelson Oliveria's penalty just seven minutes into the match.
Hosts Colombia won through to the last eight with a thrilling 3-2 win over Costa Rica in Bogata.
Trailing 2-1 with 11 minutes to play Pedro Franco levelled the score before James Rodriguez held his nerve with a coolly-taken penalty in the third minute of added time.
With the score 1-1 after 120 minutes of play, Cameroon conspired to miss all three of their spot kicks, while Mexico converted all of theirs.