Two first-half goals from Aaron Ramsey and an own goal from Kalidou Koulibaly were enough as Unai Emery's men claimed a precious win.
Aaron Ramsey goal.
Aaron Ramsey opened the scoring for the home side 15 minutes into the match after finding himself unmarked in the box and slotting home a first-time shot past Napoli goalkeeper Alex Meret into the bottom left corner.
Kalidou Koulibaly own goal.
The home team got a second goal of the night ten minutes later when Napoli defender Kalidou Koulibaly deflected the ball into his own net as he tried to block a Lucas Torreira shot.
Both sides missed glorious chances to change the scoreline with both Aaron Ramsey and Lorenzo Insigne coming close on both ends.
Having missed a huge number of clear cut chances to kill off the match, Unai Emery's men will travel to Italy next week well aware of the threat Napoli pose at home.