Dries Mertens was back on the scoresheet as Napoli closed in on second place in Serie A by surviving a late scare to defeat Roma 2-1 at the Stadio Olimpico.

Belgium international Mertens had not found the net since a hat-trick in the 7-1 pummelling of Bologna a month ago, but struck either side of half-time to send Napoli two points behind Roma - though the efforts of goalkeeper Pepe Reina were just as influential.

The greatest beneficiaries of the result could well be Juventus, though. The five-time defending champions will open up a 10-point advantage at the summit if they win away at Udinese on Sunday.

Mertens put Napoli ahead in the 26th minute when he latched on to Marek Hamsik's excellent throughball and dinked a lovely finish over the onrushing Wojciech Szczesny.

After having a goal ruled out for a trip on Federico Fazio, Mertens had the centre-back to thank for his second five minutes after the restart - Fazio's error leading to a swift Napoli break that saw the Belgian convert from Lorenzo Insigne's cross.

Roma were sluggish but finally came to life in the closing stages, substitute Mohamed Salah hitting the post before Kevin Strootman finally pulled a goal back for Luciano Spalletti's side.

They were denied a point by excellent goalkeeping from Reina, who smothered an effort from Salah before adjusting brilliantly to tip Diego Perotti's deflected strike onto the woodwork deep into stoppage time.

The Spaniard followed up that reactive save by kicking the ball away from Antonio Rudiger as he attempted to get to the rebound first, but a knock that preceded Mertens' substitution and the dismissal of coach Maurizio Sarri from the sidelines will leave a bitter taste for Napoli despite the win.