Napoli were going out before the Swiss international unleashed a powerful strike to give them the lead, then Marek Hamsik completed the 2-0 win.
“I broke the deadlock and I’m happy for myself and all the Napoli fans,” smiled Inler.
“This is an important night. We will all enjoy this victory, as we wrote Napoli history this evening.
“We want to carry on doing well. In the first half we were a little tense and it wasn’t easy, as Villarreal played good football.
“I finally scored my first goal for Napoli and want to dedicate this to all the fans who waited patiently for it to come. We deserved to qualify, we’re strong and can still really grow together.
“Now we must concentrate on Serie A and wait to know who we’ll face.”