Napoli sealed top spot in the Europa League Group I with a 3-0 triumph over Slovan Bratislava at the San Paolo stadium on Thursday.
Dries Mertens put the hosts on their way in the sixth minute before captain Marek Hamsik doubled Napoli's lead shortly after.
Duvan Zapata wrapped up the win with 15 minutes remaining.
The victory, Napoli's fourth in the group stages, ensured Rafa Benitez's side finished one point ahead of Young Boys, who won 2-0 over Sparta Prague to join the Italians in the next round.
Napoli had gone into their final group match having already qualified for the last 32 of the competition.
The Slovakians travelled to Italy with no hope of remaining in the competition after collecting just one point from their opening five games.
The home side enjoyed a strong start and took an early lead when Mertens' stinging drive from 20 yards beat Slovan goalkeeper Dusan Pernis.
Soon after, Pernis was called on to make a save to clear Christian Maggio's goal-bound effort.
Pernis could do nothing to prevent Napoli from taking a 2-0 lead in the 15th minute when Mertens' cross found Hamsik in the box and his right-footed shot hit the post before finding the back of the net.
Slovan reacted and on the half-hour mark, Samuel Stefanik's hard drive from 30 yards was saved by Napoli goalkeeper Mariano Andujar.
Pernis kept out Mertens and Duvan Zapata's close-range attempts before the interval.
Napoli continued to go forward after the re-start and in the 62nd minute Pernis made a great save from Mertens' hard drive from 30 yards.
Pernis was unable to prevent Napoli's third goal when Zapata's powerful close-range header from Faouzi Ghoulam's cross went in.