It was Bilbao that took the lead after 13 minutes when Aritz Aduriz converted from the penalty spot and he had his second just before the 30-minute mark with a finish from outside the area.
The home side had one back in the early stages of the second half when Youssef El Arabi converted from outside the box, but the scoring ended there.
Read how it all unfolded in Sports Mole's minute-by-minute live commentary below.
Granada: Tono; Ayom, Mainz, Siqueira, Diakhate; Brahimi, Benitez, Rico, Iriney; El Arabi, Torje
Bilbao: Iraizoz; Borde, Amorebieta, Iraola, Iturraspe; Susaeta, Gurpegui, Marcos; Gomez, Muniain, Aduriz