The first goal came after 12 minutes, when Guerra found the top corner of the net following Oscar's corner.
Pucela managed to restrict the visitors to speculative long-range efforts and went into the half-time break leading.
The hosts carved out a few decent opportunities to double their lead before doing so with 16 minutes remaining. Carlos Pena found Oscar inside the box, and he fired beyond Roberto Gago with his left foot.
That is the way it stayed until the final whistle, condemning Manolo Jimenez's men to their third defeat on the spin.