Roma shock high flying Napoli to dent I Partenopei's hopes of winning their first Scudetto since 1990.

Goals from Diego Perotti, Cengiz Under and a brace from Edin Dzeko stunned the San Paolo into silence on Saturday night.

The first half proved to be as frenetic a first half of football you're likely to see this season.

Inside the opening 70 seconds, AS Roma almost took a shock lead through Diego Perotti. After latching onto a loose ball inside the Neapolitan's defensive third, Radja Nainggolan burst into the right hand side of the penalty area, before brilliantly lofting the ball to the back post. Perotti however, was unable to keep his subsequent header below the crossbar, and the ball ballooned harmlessly over the head of Pepe Reina.

This early squandered opportunity proved to be a wake up call for I Partenopei, as just four minutes later, Lorenzo Insigne gave Napoli the lead. The mercurial left winger coolly side footed a Mario Rui cross from the left flank under Alisson Becker and into the back of the net.

Moments after the restart however, Napoli were pegged back by the in-form Cengiz Under. The youngster bagged his sixth goal in as many games, when his shot from the right hand side of the penalty area deflected off the foot of Rui, before looping over Reina and into the bottom right corner.

The home side were undoubtedly not disheartened by this fortunate equaliser, as they continued to press forward with explicit intent. On three separate occasions, Insigne forced the exceptional Alisson into action.

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On the half hour mark however, it was I Giallorossi who extirpated the stalemate. Edin Dzeko rose highest in the heart of the penalty area to latch onto an Alessandro Florenzi cross, and head the ball emphatically past a hapless Reina in goal.

At the start of the second half, Napoli pressed forward in droves in search of an equaliser. Like the first half, Insigne proved to be the protagonist in the Neapolitan offensive third.

Insigne came close to drawing his side level on the hour mark. After brilliantly slaloming his way past two Roma players, the diminutive winger curled the ball just past the post from fully 25 yards.

Napoli would come to rue their missed chances as in the in 72nd minute, Edin Dzeko doubled his side's lead. The towering centre forward cut in from the right flank unchallenged, before rifling the ball into the bottom left corner of the net.

The home side continued to press forward in the final quarter of an hour, but Alisson proved to be more than a match for everything Maurizio Sarri's men could throw at I Giallorossi. With 15 minutes remaining, Insigne was denied, not once, but twice by the Brazilian number one. Alisson saved both Insigne's low shot toward the near post, and the Italian's follow-up point blank effort on goal.

As Sarri's men pressed forward however, more cracks began to appear at the back; and in the 79th minute, the Neapolitan misery was compounded. Perotti latched onto a horrific attempted clearance by Rui ten yards from goal, to coolly make it 4-1.

In the 92nd minute, Dries Mertens would make the scoreline slightly more respectable, after he rifled the ball emphatically into the bottom right corner of the net from just outside the penalty area.

The result leaves Napoli just one point clear of Juventus - who have a game in hand over their fierce southern rivals. Roma, on the other hand, move up to 3rd in the Serie A table.