Aubameyang rushed onto a long ball and shoot a rebellious strike into the top corner of the net in the 23rd minute of the LaLiga match on Sunday.
He then celebrated with his trademark front flip as he ignited his career with Barca.
And after just 15 minutes he struck again shortly before the break.
A low cross was concealed by Aubameyang as he celebrated once more.
Barcelona elevated into a 3-0 led following Frenkie de Jong also got himself registered on the scoresheet in between two ex-Gunner goals.
The former Arsenal man was granted Catalan’s fourth goal, which was at first credited to Pedri, to settle his hat-trick.
Aubameyang had netted 7 times in 15 matches for Arsenal this season prior being left out in December.
He was the talk of a disciplinary contravention. This led to him being taken down as captain.
And he would not appear again for the club before his contract was ruined and he united Barcelona last month.
He has taken a notable pay reduction in order to play for the Catalans.