Aubameyang pounced in the 67th minute to restore Arsenals lead, as the forward tapped in from close range.
Bournemouth had pegged Arsenal back through Joshua King after a howler from midfielder Jefferson Lerma gifted the Gunners the opening goal.
Arsenal were not at their best against Bournemouth, and seem to miss the influence of Lacazette and benched Mesut Ozil.
But Aubameyang popped up with the winner and celebrated the 2-1 victory after the game on Instagram.
He said: I [love] tap-ins, Sead Kolasinac. Back on the win.
Lacazette was quick to jump on the Aubameyang bandwagon, sending a handshake emoji to his fellow forward.
Aubameyang replied in kind, as the strikers friendship seems to go from strength to strength.
Despite competing for a starting spot at times under Unai Emery, Aubameyang and Lacazette have repeatedly denied any tension between them.
Aubameyangs goal against Bournemouth was his tenth of the season in all competitions, while Lacazette has scored five goals in 12 Premier League appearances.
The win moved Arsenal to within a point of the top four after Chelsea were beaten for the first time this season by Tottenham.
Emery insisted Lacazettes ommission from the squad was merely a precaution, playing down concerns the Frenchman could be sidelined for the foreseeable future after sitting out the entirety of the international break.