Lionel Scaloni suggested the team produced their best performance of his tenure when fighting back from 2-0 down to draw 2-2 with Die Mannschaft on Wednesday and they looked sharp again in Spain, albeit against more modest opposition.
As soon as Argentina took the lead through Lucas Alario's header, it never looked like being anything other than a comfortable win for La Albiceleste, who went into half-time three up thanks to a Jhon Espinoza own goal and Leandro Paredes' penalty – Acuna playing a role in each of the goals.
Angel Mena pulled one back early in the second half thanks to some woeful goalkeeping from Agustin Marchesin, but it was not the start of sensational comeback, as Argentina romped to victory with German Pezzella, Nicolas Dominguez and Lucas Ocampos getting in on the act.
But for an early Michael Estrada free-kick that flew just over, Argentina dominated the first half and were good value for the lead when Alario scored for the second game running, heading Acuna's corner in with 20 minutes played.
Acuna played a decisive role again seven minutes later, Pedro Ortiz failing to keep his left-wing cross out after it took a deflection off Espinoza.
It was 3-0 soon after thanks to Paredes' spot-kick – Dario Aimar penalised for fouling Lautaro Martinez following another teasing Acuna's delivery.
Ecuador made four half-time changes and one of those introduced took just three minutes to make his mark, as Mena found the top-right corner with a 30-yard free-kick from the inside-left channel to embarrass Marchesin, who seemingly thought it was going over.
Argentina stepped things up again, however, with Pezzella re-establishing the three-goal cushion 24 minutes from time with a header from Paulo Dybala's left-wing free-kick.
Dominguez then drilled a fine drive into the bottom-left corner and Ocampos rounded off an emphatic win from a tight angle after Ortiz had parried Dybala's curler.
What does it mean? La Albiceleste starting to click
There were hints of it in the second half against Germany, but Sunday's display provided more comprehensive proof that Argentina are beginning to find their groove once again.
While Ecuador are going through a difficult moment, Scaloni's side highlighted their technical qualities while working hard in a thoroughly professional showing.
Acuna stakes his claim
Nicolas Tagliafico's stranglehold on the left-back spot has frustrated some fans in recent times, particularly after a difficult outing against Germany. Acuna came in on Sunday and showed why many are calling for him to get a run in the side. Even if it was only against Ecuador, he was a constant threat on the left and his deliveries were exceptionally consistent.
Marchesin loses his bearings
Several Ecuador defenders produced unimpressive displays, but Argentina's Marchesin will go down as the flop of the match after his suspect goalkeeping for Mena's goal – the Porto man inexplicably letting it float over his head and into the net.
Scaloni's men return to action next month in another friendly, as they face Paraguay in Bangladesh. Ecuador are yet to schedule any fixtures for the November international break.