Inter Milan sent a warning to the rest of Serie A with Sunday’s convincing 3-0 win at Napoli which re-established their two-point lead at the summit and left the champions’ title defence on its last legs.

Beautifully taken goals from Hakan Calhanoglu, Nicolo Barella and Marcus Thuram pushed Inter back above closest challengers Juventus, who briefly held top spot after beating Monza on Friday.

Sunday’s thumping was a show of force from Inter who illustrated why they are favourites to win a 20th league title, still unbeaten away from home in all competitions after claiming a huge win at a ground where they have a dreadful record.

“It was a show of strength, of team spirit,” said Inter coach Simone Inzaghi.

“Winning like this in Naples is satisfying, but we’re only 14 games in and there is a very long way to go.”

Napoli are now 11 points off the pace and travel to Juve next weekend in a match which could end any realistic hope of the champions retaining the Scudetto before the calendar year is out.

To add insult to injury Napoli have dropped out of the top four, replaced by Roma who won 2-1 at Sassuolo earlier and sit in the last Champions League spot on goal difference.

Napoli recriminations

Returning Napoli coach Walter Mazzarri refused to speak after the match, sporting director Mauro Meluso expressing anger at referee Davide Massa for not stopping play for a foul before Inter’s opener and not giving a penalty for what he believed was a clear foul on Victor Osimhen while the home side trailed by a single goal.

“I don’t want to create an excuse for our team, who obviously still need to work on a few things, but we didn’t deserve that humiliation today,” said Meluso.

Simone Inzaghi’s side have won 11 of their 14 league matches so far this season and once Hakan Calhanoglu thrashed in the opener on the stroke of half-time they expertly dealt with a hyped-up Napoli.

Hosts Napoli were playing their first home fixture under Mazzarri, whose team are stuck on a paltry seven points from as many matches at the Stadio Diego Armando Maradona.

Barella doubled Inter’s lead just after the hour mark with his first goal of the season shortly after Yann Sommer pulled off a brilliant save to deny Khvicha Kvaratskhelia, one of three superb stops from the Swiss.

Italy’s Barella burst unopposed from midfield and after collecting Lautaro Martinez’s low pass skipped past Leo Ostigard and Natan before confidently finishing past Alex Meret.

And with five minutes remaining Thuram — who earlier had a goal ruled out for a microscopic offside — made absolutely sure of the points, tapping home his fifth league goal of a brilliant first season at Inter from substitute Juan Cuadrado’s low cross.

Paulo Dybala’s 76th-minute penalty and a wildly deflected strike from Rasmus Kristensen shortly afterwards earned Roma a win from their scrappy match with 10-man Sassuolo, who opened the scoring through Matheus Henrique.

The win at the Mapei Stadium came as coach Jose Mourinho is reportedly being investigated by the Italian Football Federation for saying that referee Matteo Marcenaro didn’t “have the emotional stability to referee at this level” ahead of the match.

The Portuguese blasted Marcenaro, 31, in a pre-match outburst on Saturday which the country’s refereeing association said “could lead to violence” against officials.

And despite having excellent Italian Mourinho insisted on only speaking in Portuguese in his post-match interview with DAZN.

“I am speaking Portuguese because my Italian is not good enough to explain certain concepts,” claimed Mourinho.

“When I spoke about emotional stability, I was talking about a quality that is necessary in both life and football in order to perform at the highest level.”

Fiorentina are a point behind Roma and Napoli in sixth thanks to a simple 3-0 win over the division’s bottom team Salernitana, while Bologna are a further point and place back following their 1-1 draw at Lecce.