Made a couple of comfortable saves in the first half and will be relieved to see the woodwork twice come to his rescue in the second period.
Dealt admirably with any aerial attacks and closed Eder well, but was often exposed when Sampdoria got runners forward from deeper positions.
Made good inroads down his flank early on but began to struggle with Gabbiadini and was replaced by Armero early in the second half.
Performed well enough alongside Albiol but never looked totally comfortable once Eder woke up late in the first half.
Anonymous in the first half but for one typical long-range effort. More effective in the second period without ever truly bossing the middle.
A decent defensive shift but was not as effective going forward as he would have liked.
Began to exert control in the middle after a frantic opening period, but never really seized charge of midfield alongside Inler.
A lively link in Napoli's mobile attack, he caused plenty of problems for the Sampdoria defence with his runs in and around the area.
The weakest of Napoli's attacking players. His runs were effective and he looked a threat at times, but he spurned two clear chances in the second half to put a gloss on the performance.
Delivery often let him down but he looked a threat when going for goal himself, taking his opener with consummate style after Da Costa had earlier thwarted him. Excellent free kick for his second, too, just minutes after another poor use of a corner.
Should have scored when he volleyed straight at Da Costa, but teed up Mertens well for the first goal. Booked for dissent in the first half and was replaced as a precaution late on.
Angelo Da Costa
Brilliant early save from Higuain and alert to deny Mertens. Could do nothing about the opener but will be disappointed to have seen Mertens' free kick get beneath his hand.
Dealt with Insigne fairly well but offered very little support to Gabbiadini and Co. when Sampdoria broke forward. Caught out of position too often.
Covered the lines well as Napoli's forwards darted into spaces but couldn't stop Mertens from ghosting in for his first.
Booked for a lunge in the first half as he tried to get to grips with Higuain. He never managed it.
L. De Silvestri
Struggled early on with Mertens' movement but grew into proceedings and was one of his side's stronger defensive presences. One bustling run forward brought a save from Raffael.
Strong in the air but never looked comfortable against the home attack's movement.
A lively link to the Sampdoria attack, but he began to grow tired and frustrated once Napoli doubled their lead and was eventually replaced.
Anonymous display. Never got to grips with things in midfield and offered next to nothing going forward. Booked for a daft handball.
Created a handful of chances but, as with Krsticic, seemed to lose his legs from under him as the match wore on.
Offered no outlet early on but brightened towards the end of the first half and began to threaten. Linked play well in the second period and twice tested Raffael.
Sampdoria's brightest player. Looked a danger whenever he cut infield and fired a brilliant shot which thundered off the underside of the bar just after Mertens' goal.
Replaced Regini and put in a good shift on the left.
Set up Pozzi for his effort and looked bright but was denied any clear service as Napoli saw the game out.
Contrived to fire a shot off both posts with his first action in the game. Looked lively in the latter stages.