Philip Billing's late strike earned Napoli a hard-fought 1-1 draw against Serie A leaders Inter Milan at home on Saturday, keeping the title race tightly contested with just a single point separating the top two sides.

Federico Dimarco's stunning 22nd-minute free kick gave defending champions Inter the lead, silencing the partisan crowd at the Diego Armando Maradona Stadium. However, Danish midfielder Billing emerged as Napoli's hero, coming off the bench to equalize in the 87th minute with a clinical finish.

The result leaves Inter on 58 points, one ahead of Napoli (57), while third-place Atalanta remained two points further back after being held to a goalless draw by Venezia.

After a nervy, scrappy start from both sides at the Diego Armando Maradona Stadium, with the game repeatedly interrupted as players received treatment, it was only fitting that the opening goal came from a set-piece.

Dimarco curled his free kick around the wall and inside the far post. Napoli goalkeeper Alex Meret could only look on as the ball nestled in the corner of the net and the game finally erupted into life.

Once Napoli absorbed the sucker-punch, they began to push forward in search of an equaliser. A long pass was met first time by striker Romelu Lukaku but his effort smashed into the side netting.

Seconds later Giacomo Raspadori's first touch took him past Inter keeper Josep Martínez wide in the area but his second was too heavy and the ball rolled wide with Lukaku waiting in the middle of the area.

Just before the break Raspadori managed to get the ball into a dangerous position but Lukaku's strike from the edge of the six-yard box was blocked by Alessandro Bastoni and Inter held their lead going into the interval.

Napoli were camped out in the Inter area for much of the second half, forcing corner after corner. Stanislav Lobotka fired over from the edge of the area after a one-two with Lukaku.

Scott McTominay then had a powerful strike parried away by Martinez, while an Inter counter-attack needed Meret to come well out of his area and clear the danger with Denzel Dumfries bearing down on the Napoli goal.

Napoli were looking to put a dismal February behind them where a run of three draws and one defeat had allowed Inter to steal top spot, but they looked set to slip further behind until manager Antonio Conte sprang Billing from the bench.

The Dane, signed on loan from Bournemouth in January, made his Napoli debut in last weekend's defeat at Como but needed just eight minutes to make his mark against Inter.

Played in by Lobotka, Billing's first effort was saved by the leg of Martinez but he poked home the rebound to keep Napoli's title hopes very much alive.