Napoli captain Marek Hamsik says they're back to their best after victory at Cagliari.

Napoli won 5-0 in Sardinia, with Dries Mertens hitting a hat-trick.

"You are right, it's hard to find a better performance, it was a victory of the team, we all made a great performance," said Hamsik.

"For two years we are playing great football, there's been a few games that we did not win and we did a little 'bad', but seeing the latest performance we're returning to the real Napoli.

"Sometimes we lack the mental strength, but today at 2 to 0, we continued to play and we finished the game with more goals."