Marek Hamsik had the first chance of the game for the visitors, but after receiving the ball in space on the edge of the box, he fired a low strike just wide of the goal.

Napoli's Blerim Dzemaili is congratulated by teammates after scoring the opening goal against Sassulo in their Serie A match on February 16, 2014 © Getty Images

Hamsik threatened for Napoli again minutes later, but once more he failed to trouble the keeper with a shot from distance.

Sassuolo then came close to breaking the deadlock through Antonio Floro Flores, who drilled a free kick narrowly wide of the post.

The visitors wasted a big opportunity to open the scoring when Gonzalo Higuain latched onto a ball over the top from Hamsik, but he could only direct his effort straight at the keeper.

The Naples outfit came close again moments later. Lorenzo Insigne was slipped into the box, but he saw his shot beaten away by Gianluca Pegolo.

Napoli continued to press and Pegolo had to be alert again to deny Higuain's fierce shot from close range.

Napoli's Lorenzo Insigne scores his team's second goal against Sassuolo during their Serie A match on February 16, 2014 © Getty Images

In the 37th minute the visitors made their dominance pay as Blerim Dzemaili latched onto a loose ball just outside the box and fired into the bottom corner.

The Azzurri doubled their lead 10 minutes into the second half when Insigne was played in by Hamsik down the left hand side, before cutting in and curling an effort past Pegolo.

Simone Zaza came close to pulling a goal back for Sasuolo, but he dragged his shot wide when well-placed inside the box, before Nicola Sansone saw a fierce attempt pushed away by Rafael.

Insigne should have added a third when he was played through on goal, but with just the keeper to beat, he fired wide of the far post.

In the closing stages Dzemaili fired an effort against the bar and Mertens saw a shot saved after weaving his way into the area, as Napoli held on to the win and moved to within one point of Roma in the table.