Goals from Gokhan Inler and Hamsik helped the Italian side to the crucial three points they needed to stay ahead of Manchester City and qualify as group runners-up, and the Slovakia international was absolutely ecstatic.
"It's a crazy sensation now that we have achieved this. We are so happy. It's 21 years since we reached this stage in the European Cup, so this is fantastic," Hamsik was quoted as saying on the Uefa website.
"Napoli have football-crazy fans, which you can see by the fact that 5,000 of them have followed us here.
"When the group was drawn we knew it was a very hard one, but today we have 11 points and that's a fantastic achievement. Now we'll wait to see which team we are going to play next."
The draw for the Champions League round of 16 takes place on Friday December 16.
How do you stay up to date with football when on the move? With http://m.goal.com – your best source for mobile coverage of the beautiful game.