Leonardo Mayer and Federico Delbonis came through their Argentina Open first-round matches on Monday.
Mayer, a wildcard at the ATP 250 event played on clay in Buenos Aires, battled past Portugal's Gastao Elias 4-6 6-4 6-4.
The Argentinian made a slow start before breaking once in both the second and third sets.
His win sees him advance to a clash against either countryman Guido Pella or Spanish fifth seed Albert Ramos-Vinolas.
Delbonis was far more comfortable, taking just over an hour to thrash Frenchman Stephane Robert 6-3 6-1.
The Argentinian will face either Horacio Zeballos or Joao Sousa before a potential meeting with top seed Kei Nishikori.