Aritz Aduriz continued his remarkable scoring record against Granada, netting a hat-trick in a 4-0 victory on Friday.
The attacker went into the game having scored his side’s last three goals in matches with Granada, and did not take long to get on the scoresheet again this time around.
Aduriz headed home after seven minutes to get Bilbao off to a wonderful start, before firing in a superb 20-yard strike off the angle of post and crossbar to double the hosts’ advantage 11 minutes later.
Granada captain Diego Mainz was given his marching orders in the 73rd minute when he brought down Aduriz in the box, and the undoubted man of the match made no mistake in sending the resulting penalty down the middle and beyond Roberto from 12 yards.
Carlos Gurpegi completed the rout 10 minutes from time, volleying home from the edge of the area after Granada had failed to clear their lines from a cross.
The win lifts fourth-placed Bilbao seven points clear of Villarreal and Real Sociedad, who each play on Sunday, in the battle for UEFA Champions League qualification.
Granada have now lost five of their last six league outings and remain 13th.