The Spaniard won through against compatriot Nicolas Almagro in a repeat of the 2012 final, as he reached the showpiece of the ATP 250 event.
Two years earlier, it had taken Ferrer three sets to dispose of Almagro but he was far more comfortable on this occasion, winning 6-4 6-2 in just 86 minutes.
The top seed, who also won the tournament in 2013, was dominant on serve in the opener in Buenos Aires, winning 21 of 28 points on first serve.
And when he did slip up, he produced his best tennis, saving all three break points he offered Almagro and taking his only one at the first opportunity.
Almagro wilted in the second set, landing just 47 per cent of first serves, giving Ferrer ample chances to break.
He took three of them as the world number five set up an exciting final against Italian Fabio Fognini.
Fognini produced an excellent comeback to defeat Spain's Tommy Robredo 3-6 7-5 6-3.
The world number 14 - who has made five consecutive ATP World Tour finals on clay and won 23 of his last 24 matches on the surface – made a slow start, serving poorly.
Two breaks in the opener gave Robredo the early initiative and the third seed should have closed out the match in the second set.
He served for the contest at 5-3, but was broken at a crucial time as Fognini dug deep.
Robredo lost four successive games to concede the second set and that gave his opponent all the momentum he needed to clinch victory.
Fognini took just five of his 13 chances to break though, and will know he needs to be more clinical in Sunday's showpiece if he is to stop Ferrer's golden run at the event.
A win in the final would lift Fognini to 13th in the world as he continues his charge for a spot inside the world's top 10.
The last Italian player to crack the top 10 in the men's game was Adriano Panatta in 1978.