Juventus coach Massimiliano Allegri claimed the Serie A title race is far from over after Juan Cuadrado's sensational first-half strike earned a 1-0 win over Inter Milan to send the Turin giant six points clear of Napoli on Sunday.

Roma, which is seven points back in third, can leapfrog Napoli into second with a win over Fiorentina on Tuesday.

However, the capital club is reeling from last week's loss to Sampdoria and is under pressure not to fall further behind Juve.

Inter traveled west hoping to build on a superb spell that has earned Stefano Pioli's men 25 points from 10 games.

But poor finishing and dogged Juve defending kept Inter at bay before Cuadrado's slightly deflected shot earned victory on 45 minutes.

Juve held on, amid a bad-tempered second half which saw Ivan Perisic sent off in the final minute, to secure an 18th win that kept it on course for a record sixth straight title.

"We're not going to say we have one hand on the scudetto, but this is a very important step," Allegri said.

"I'm sure Napoli and Roma have yet to collect a lot of points, but in the meantime we've kept Inter at bay."

Inter remains fifth, 12 points behind leader Juve and five behind Roma in the third and final Champions League qualification spot.

Inter coach Stefano Pioli claimed his side was denied two clear penalties in the first half following what he claimed were fouls on Mauro Icardi by Mario Mandzukic and Giorgio Chiellini.

If there was any consolation for Inter, it was seeing city rival AC Milan slip to a third consecutive loss after Luis Muriel's second-half spot kick earned a 1-0 win for visitor Sampdoria.

Milan coach Vincenzo Montella had raised hopes the seven-time European champion could battle for a Champions League spot for the first time since 2014.

However, injuries to midfielder Giacomo Bonaventura, who is out for the season, and defenders Mattia Di Sciglio and Luca Antonelli forced Montella into fielding a makeshift back four.

Alessio Romagnoli and Juraj Kucka were hauled back into defense from midfield and the enforced changes exacted a toll.

When Gabriel Paletta hauled down Fabio Quagliarella, Muriel netted the resulting 70th-minute spot-kick.

Milan is eighth, 17 points behind Juve.

"The Europa League is our primary objective," said Montella.

Elsewhere on Sunday, Marco Parolo netted four goals - three with his head - as Lazio hammered cellar dweller Pescara 6-2 to maintain its Champions League challenge.

Lazio is fourth, four points behind Roma.

Palermo gave its relegation dogfight a shot in the arm with a 1-0 win over 10-man Crotone that kept the Sicilians third from the bottom, eight points from safety.