Neither side could make the breakthrough in the first period, with chances remaining few and far between in a tight 45 minutes of football.
Bilbao eventually took the lead after 67 minutes, however, when Aritz Aduriz found the back of the net with a powerful header.
Read how it all unfolded in Sports Mole's minute-by-minute live commentary of the action below.
BILBAO: Iraizoz; Iraola, San Jose, Ekiza, Laporte; Gurpegi, Susaeta, Herrera; Aduriz, De Marcos, Ibai
GRANADA: Tono; Angulo, Nyom, Mainz, Lopez; Ortiz, Nolito, Rico; Brahimi, Ighalo, El-Arabi
End-to-end football in the last couple of moments as both sides begin to open up, but neither can find that elusive pass in the final third. The first yellow card of the match arrives as Susaeta is booked for a late challenge on Mainz. Meanwhile, the fourth official indicates that we will play an additional one minute at the end of the half.