Goals from Pite, Jose Velazquez and Andre Silva earned Arouca a convincing victory in Wednesday's reverse fixture at Estadio Municipal de Arouca.
Match preview
Rio Ave snapped an 11-match winless run with a late 2-1 win at Nacional on the final day of the regular season, but that was not enough to lift them out of the bottom three.
Miguel Cardoso's side finished one point behind Maritimo and Portimonense as they were made to pay for that two-month gap between top-flight victories.
The Carlos Mane-inspired win against Maritimo at least provided the Rioavistas with some momentum heading into the playoff first leg with Arouca, but that did not show on the day.
Rio Ave were outclassed and now need to score at least three times - something they have managed only three times since June - if they are to remain a Primeira Liga side.
Arouca have not played in the top tier of Portuguese football since 2015, though that is surely about to change thanks to their strong first-leg showing.
Indeed, the Arouquenses were somewhat unfortunate to miss out on automatic promotion at the end of the regular season as they strung together a nine-game winning run.
Despite that incredible run, Arouca still finished one point behind second-placed Vizela and five behind winners Estoril.
Accounting for their win against Rio Ave earlier this week, Armando Evangelista's men have now won 10 in a row and kept seven clean sheets across those fixtures.
After a six-year absence, Arouca are now just 90 minutes away from sealing their return back in the big time - and nobody can argue it is not deserved.
Rio Ave form (all competitions):
Arouca form (all competitions):
Team News
Rio Ave were once again without experienced defender Fabio Coentrao for the first leg, so Ivo Pinto and Pedro Amaral will likely operate in the full-back positions on Sunday.
Gelson Dala retained his spot in midweek and, despite scoring only three goals in 31 regular-season matches, he is expected to get the nod up top once again here.
Among those pushing for recalls to the side are Junior Brandao and Savio, who were both introduced from the substitutes' bench in the first leg.
As for the visitors, Evangelista will surely see little reason to change things around here on the back of the professional display last time out.
Pite's opener at Estadio Municipal de Arouca was his third goal in two matches, and he will be used alongside fellow goalscorer Andre Silva.
Lawrence Ofori was brought on at half time in the 3-0 win earlier in the week and is in contention for a starting spot should Evangelista opt to change things slightly.
Rio Ave possible starting lineup:
Kieszek; Pinto, Borevkovic, Santos, Amaral; Guga, Pele, Augusto; Mane, Dala, Meshino
Arouca possible starting lineup:
Braga; Thales, Basso, Velazquez, Quaresma; Bukia, Leandro Silva, Moreira, Arsenio; Pite, Andre Silva
We say: Arouca 0-0 Rio Ave (0-3 on aggregate)
After five successive top-seven finishes in the Primeira Liga, Rio Ave are on the brink of dropping down to the second division.
Arouca did all the hard work in the first leg and, on the basis of their impressive defensive record, we can see them completing the job in a stress-free manner.