Radja Nainggolan grabbed the equaliser in a 1-1 draw for Cagliari to dent the title ambitions of his parent club Inter Milan, who struggled to a third consecutive stalemate on Sunday.

Tensions reached boiling point at the San Siro as Inter’s goalscorer Lautaro Martinez was sent off in injury time for arguing with the referee.

The Argentinian risks a long suspension after reacting with fury, shouting and repeatedly punching the plexiglass at the side of the pitch, after being led away by his teammates.

Antonio Conte’s second-placed Inter are now three points adrift of leaders Juventus, who travel to 13th-placed Napoli later on Sunday.

They can also be caught by Lazio, in third, who are three points behind before their derby clash against fourth-placed Roma.

A win would see Simone Inzaghi’s Lazio join Inter in the standings, with a game in hand to be played in February against Hellas Verona.

Martinez’s frustration mirrored that of his team who have now been held to three consecutive 1-1 draws -- at home against Atalanta and Cagliari and at Lecce. Inter have taken 11 points from the last seven games, not enough to keep pace with eight-time reigning champions Juventus.

Meanwhile, Josip Ilicic hit a hat-trick, including a sensational strike from the halfway line, as Atalanta crushed Torino 7-0 in Serie A on Saturday, inflicting the worst home defeat ever on their northern rivals who finished the match with nine men.

The Slovenian forward opened the scoring on 17 minutes, adding two more in quick-fire succession eight minutes after the break.

Substitute Luis Muriel also bagged a late brace to add to first-half goals by Robin Gosens and Duvan Zapata.

The hosts played the final quarter of an hour a man down after Armando Izzo was sent off, with Sasa Lukic joining him with just a minute to go.

Torino coach Walter Mazzarri blasted an “indefensible performance”.

“All we can do is apologise,” he said. “In so many years of my career I had never had such a game.”

But the Torino coach ruled out quitting.

“Resignation? No, in difficulties I never leave.”

Gian Piero Gasperini’s Atalanta hit back after last weekend’s shock defeat to lowly SPAL, following a draw against Inter Milan.

They now join Roma in fourth place on 38 points.

“Ilicic is decisive, not only in the penalty area, he is a continuous creator,” said Gasperini. “Most of our attacking game is built around him.”

Roma occupy the final Champions League spot on goal difference before they take on local rivals Lazio in Sunday’s derby in the Stadio Olimpico.

In-form Ilicic pounced on an early error from Torino defender Diego Laxalt, with Gosens volleying in the second just before the half hour.

Atalanta were awarded a penalty after Lukic fouled Ilicic with Zapata stepping up to slot in from the spot for his first goal after returning from a three-month injury layoff.

Ilicic got his second in sensational style after 53 minutes when he spotted Sirigu off his line and sent a free-kick sailing long distance from just inside the halfway line and over the head of the Torino goalkeeper. The Slovenian then picked up a Zapata cross a minute later to complete his hat-trick with his 13th goal this season.

Torino were in disarray after Izzo was sent off for a second yellow card.

Muriel came on with seven minutes to go and slotted in a penalty awarded for a Soualiho Meite foul on Rafael Toloi.

The Colombian added his second just two minutes later, finishing off a Papu Gomez cross.

Lukic was sent off to compound the woes of tenth-placed Torino.

Captain Andrea Belotti brought the team over to the home stand to apologise, but the fans responded with whistles.

In Tuscany, goalkeeper Bartlomiej Dragowski saved a penalty and pulled off key saves to rescue a point for Fiorentina in a goalless draw against struggling Genoa.

Dragowski kept out a penalty from Genoa captain Domenico Criscito after just quarter of an hour in Tuscany.

Agence France-Presse