Duvan Zapata scored a goal of sheer brute force and determination to set Napoli on the way to a 2-0 win over Sassuolo which moved them another step closer to second-placed AS Roma in Serie A on Monday.
Mauro Icardi scored his 14th league goal of the season to give Inter Milan a 2-1 win at Cagliari in Monday's other game, pushing Gianfranco Zola's side closer to Serie B.
Napoli had spent just over one hour banging away at the Sassuolo rearguard when Zapata collected Marek Hamsik's pass and ran towards the centre of the retreating defence.
The burly Colombian fell over when his shot was blocked but, despite being surrounded by four defenders, leapt to his feet, got to the ball first and then managed to place it into the net, leaving three bemused opponents sprawled on the pitch.
Zapata, who only started because Gonzalo Higuain was suspended, then provided the pass for Hamsik to score the second with a curling shot.
“It’s not easy to leave Zapata on the bench but he's got Higuain in front of him," coach Rafael Benitez told reporters.
"He just needs to continue working hard like he has done in the last few days."
Napoli saw out the win despite having substitute Dries Mertens sent off after only six minutes on the pitch. The Belgian midfielder was given a straight red card for a trip from behind, although it seemed a harsh decision.
Third-placed Napoli, who were nine points behind Roma before the Christmas winter break, cut the gap to three points as they moved onto 45 points from 24 games.
Benitez's team have won six out of eight league games since the start of January.
Mateo Kovacic put the finishing touch to a flowing move to put Inter ahead two minutes into the second half and Icardi extended their lead with a solo effort, making him joint topscorer alongside fellow Argentine Carlos Tevez of Juventus.
Cagliari had wasted chances in between the goals and finally pulled one back when Samuele Longo won possession off Juan Jesus, rifled a volley against the post and the ball rebounded into the goal off Inter goalkeeper Juan Pablo Carrizo.
The Sardinians, who did more than enough for a point, were left stranded in 18th place in the 20-team table, three points adrift of Atalanta and safety. Inter climbed to eighth with 35 points.