Granada went into the match just four points above the drop zone, while Athletic were two places and four points better off.
Granada were without a win in five and their lack of confidence showed early on as Athletic dominated.
Aduriz's 12th-minute effort whistled just past Antonio Tono's post, but the goalkeeper was to be called into action eight minutes later to keep out Ander Herrera's shot and then Markel Susaeta's header.
However Athletic have had problems at the back all season as only the bottom two - Deportivo and Real Mallorca - have conceded more league goals than the Basque outfit.
And Granda came close to making it goal number 52 against Marcelo Bielsa's side when after 24 minutes Manuel Agudo Nolito headed against the bar from six yards out.
Tono had to be alert to parry Aduriz's header, before Oscar de Marcos shot over for Athletic when just 12 yards out, as Granada entered the dressing room at half-time lucky to be level.
Aymeric Laporte header tested Tono eight minutes after the restart, before Gorka Iraizoz in the Athletic goal was tested for the first time by Youssef El Arabi.
Seven minutes later and Athletic were ahead when Aduriz headed home Gomez Ibai's cross from six yards out and it was a lead they would not relinquish.
Susaeta saw red after picking up his second yellow following a foul on Nolito, but Athletic failed to threaten.