Top seed Berdych saw off Victor Hanescu 6-2 6-2 to continue his impressive form at the ATP 250 event and remain on course for a third career clay-court title.
He will need to overcome Argentine Berlocq in his 22nd tour-level final, after the world number 62 came through 7-6 (8-6) 6-2 against Daniel Gimeno-Traver.
Berdych's encounter with Hanescu began with the pair each holding serve on two occasions before the Czech's class showed.
He reeled off the final four games of the opening set, before moving 3-0 ahead in the second during what was a dominant performance.
Hanescu demonstrated determination by winning a further two service games, but Berdych proved too strong.
In the other last-four tie, Berlocq brought an end to the journey of Spanish qualifier Gimeno-Traver, but had to come through a hard-fought first set.
From 6-5 down in a tie-break, Berlocq turned on the quality to secure three points on a spin and then bounced back from a game down to lead 3-1 in the second set.
Gimeno-Traver had no answer and Berlocq will now target a first win over Berdych after losing their previous three meetings.