A performance of bravery allied to goals from the strike pairing of Giuseppe Rossi and Nilmar edged Villarreal CF past a stubborn SSC Napoli side 2-1 on the night and on aggregate.
Walter Mazzarri's team had led through Marek Hamšík and struck the woodwork twice in the second half but the Yellow Submarine progressed to face Bayer 04 Leverkusen in the round of 16.
Ezequiel Lavezzi twice gave warning of the opening goal before he actually created it. The Argentina international shot both wide and high when Villarreal's defence left him unmarked in quick succession but his 18th-minute cross was precision itself. Hamšík timed his run to dive and nod the ball past the stranded Diego López.
Given that Villarreal had only registered two goals in five previous matches and Napoli were controlling possession, the picture looked grim for Juan Carlos Garrido's side. However, four straight wins and an 11-1 goal aggregate at home in the UEFA Europa League this season proved more apposite.
Even when it was requiring last-ditch interceptions to stem the tide of light-blue attacks, Santi Cazorla, Borja Valero and Cani worked Villarreal back into the game. Borja struck a powerful shot just wide and Cani glanced a header into the arms of Morgan De Sanctis.
Suddenly the flow of confidence became the glow of success. Three minutes before the break Borja threaded a cute pass towards the overlapping Nilmar who scored across De Sanctis. Then in additional first-half time Nilmar foraged, won the ball superbly and fed Borja. For the second time the Spanish international passed with vision and Rossi's goal-bound shot deflected over the custodian.
Napoli's response was admirable, substitute Edinson Cavani performing heroically, hitting the post with a fearsome shot and generally causing havoc. Lavezzi also struck the frame of the goal, direct from a 76th-minute corner but to no avail.