The striker headed home the opener and fired in a fine 20-yard second to put the hosts in total command inside 20 minutes.
Aduriz then won the penalty which earned defender Diego Mainz a red card and allowed him to complete his hat-trick in the 73rd minute.
Carlos Gurpegi sealed a success which puts fourth-placed Athletic seven points clear of Villarreal.
The hosts came flying out of the blocks and Aduriz nodded them ahead after seven minutes, diverting Andoni Iraola's right-wing cross into the bottom corner.
His second 11 minutes later was rather less routine as he rounded off a flowing move by smashing a shot from the right channel which swerved away from goalkeeper Roberto and nestled in the top corner.
Athletic were in complete control, with Granada unable to get a look-in, and the dominance continued into the second half.
Ander Herrera's long-range effort brought a superb parry out of Roberto, but he was helpless in the 73rd minute.
Aduriz was fouled in the area by Mainz and, after the defender had seen red, the Athletic striker stepped up to slot the penalty low into the net.
Riki finally worked home keeper Gorka Iraizoz with a shot from way out, but things continued to get worse for Granada as Athletic grabbed a fourth 10 minutes from time.
Gurpegi added his name to the scoresheet with a left-footed shot high into the net.
And the hosts kept going, Iker Muniain twice bringing smart stops out of Roberto in stoppage time, as they remained firmly on top until the final whistle.