We doubled our advantage just 10 minutes later when Aubameyang combined with Ramsey before crossing for Ainsley Maitland-Niles to head home at the far post for 2-0 in the 15th minute.
ARSENAL (3-4-1-2): Cech, Mustafi, Koscielny, Monreal, Maitland-Niles, Xhaka, Ramsey (Torreira 87), Kolasinac; Ozil (Mkhitaryan 69); Lacazette (Iwobi 69), Aubameyang.
Rennes gave Arsenal a real scare shortly after the half-time restart as Ismaila Sarr picked out the post with his shot, which took a touch on its way through, after Shkodran Mustafi was caught on the ball.
After scoring Aubameyang donned a Black Panther mask to celebrate, and he explained why afterwards. Well, that was until Aubameyang struck in the second half to complete his brace and extended their lead.
Gabon global Aubameyang is more used to featuring in the Champions League than Europe's second-tier competition, but his early impact with a goal and an assist was decisive for the Gunners.
Rennes pushed for an away goal but Aubameyang scored a third late in the second-half to seal Arsenal's progress.
Arsenal are through to the next round of the Europa League after mounting a mighty comeback against Rennes. The late goal was the forward's second of the night, and it all but sealed Arsenal's place in the Europa League quarterfinals.