After claiming their first title since 2015 as a couple, Di Nenno and Stupaczuk were pushed to the brink in both sets in their Austrian bow.
They beat Salva Oria and Nacho Vilariño 7-5 7-6 on Wednesday, punching their ticket to the round of 16.
Local heroes and Austrian number ones Rainhard Boisits and Kristopher Sotiriu were in action too, trying to spring a surprise on Javi Rico and Leandro Augsburger.
Watch all of Wednesday's centre court highlights in the video below!
Matches in chronological order:
Martin Di Nenno (ARG) / Franco Stupaczuk (ARG) (2) vs Salva Oria (ESP) / 'Nacho' Vilariño (ESP)
Javi Rico (ESP) / Leandro Augsburger (ARG) vs Rainhard Boisits (AUT) / Kristopher Sotiriu (USA) (W.C.)
Fede Chingotto (ARG) / 'Paquito' Navarro (ESP) (4) vs Pablo Cardona (ESP) / Ivan Ramirez (ESP)